| 1. |
- Becker, Holger, et al.
(författare)
-
Microfluidic system for the identification of bacterial pathogens causing urinary tract infections
- 2015
-
Ingår i: Microfluidics, BioMEMS, and Medical Microsystems XIII. - : SPIE - International Society for Optical Engineering. - 9781628414103
-
Konferensbidrag (refereegranskat)abstract
- Urinary tract infections (UTIs) are among the most common bacterial infections and pose a significant healthcare burden. The growing trend in antibiotic resistance makes it mandatory to develop diagnostic kits which allow not only the determination of a pathogen but also the antibiotic resistances. We have developed a microfluidic cartridge which takes a direct urine sample, extracts the DNA, performs an amplification using batch-PCR and flows the sample over a microarray which is printed into a microchannel for fluorescence detection. The cartridge is injection-molded out of COP and contains a set of two-component injection-molded rotary valves to switch between input and to isolate the PCR chamber during thermocycling. The hybridization probes were spotted directly onto a functionalized section of the outlet microchannel. We have been able to successfully perform PCR of E. coli in urine in this chip and perform a fluorescence detection of PCR products. An upgraded design of the cartridge contains the buffers and reagents in blisters stored on the chip.
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| 2. |
- Bleiker, Simon J., et al.
(författare)
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High-Aspect-Ratio Through Silicon Vias for High-Frequency Application Fabricated by Magnetic Assembly of Gold-Coated Nickel Wires
- 2015
-
Ingår i: IEEE Transactions on Components, Packaging, and Manufacturing Technology. - : IEEE Press. - 2156-3950 .- 2156-3985. ; 5:1, s. 21-27
-
Tidskriftsartikel (refereegranskat)abstract
- In this paper, we demonstrate a novel manufacturing technology for high-aspect-ratio vertical interconnects for high-frequency applications. This novel approach is based on magnetic self-assembly of prefabricated nickel wires that are subsequently insulated with a thermosetting polymer. The high-frequency performance of the through silicon vias (TSVs) is enhanced by depositing a gold layer on the outer surface of the nickel wires and by reducing capacitive parasitics through a low-k polymer liner. As compared with conventional TSV designs, this novel concept offers a more compact design and a simpler, potentially more cost-effective manufacturing process. Moreover, this fabrication concept is very versatile and adaptable to many different applications, such as interposer, micro electromechanical systems, or millimeter wave applications. For evaluation purposes, coplanar waveguides with incorporated TSV interconnections were fabricated and characterized. The experimental results reveal a high bandwidth from dc to 86 GHz and an insertion loss of <0.53 dB per single TSV interconnection for frequencies up to 75 GHz.
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| 3. |
- Carlborg, Carl Fredrik, et al.
(författare)
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A High-Yield Process for 3-D Large-Scale Integrated Microfluidic Networks in PDMS
- 2010
-
Ingår i: Journal of microelectromechanical systems. - 1057-7157 .- 1941-0158. ; 19:5, s. 1050-1057
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents an uncomplicated high-yield fabrication process for creating large-scale integrated (LSI) 3-D microfluidic networks in poly(dimethylsiloxane) (PDMS). The key innovation lays in the robust definition of miniaturized out-of-plane fluidic interconnecting channels (=vias) between stacked layers of microfluidic channels in standard PDMS. Unblocked vias are essential for creating 3-D microfluidic networks. Previous methods either suffered from limited yield in achieving unblocked vias due to residual membranes obstructing the vias after polymerization, or required complicated and/or manual procedures to remove the blocking membranes. In contrast, our method prevents the formation of residual membranes by inhibiting the PDMS polymerization on top of the mold features that define the vias. In addition to providing unblocked vias, the inhibition process also leaves a partially cured, sticky flat-top surface that adheres well to other surfaces and that allows self-sealing stacking of several PDMS layers. We demonstrate the new method by manufacturing a densely perforated PDMS membrane and an LSI 3-D PDMS microfluidic channel network. We also characterize the inhibition mechanism and study the critical process parameters. We demonstrate that the method is suitable for structuring PDMS layers with a thickness down to 10 mu m.
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| 4. |
- Carlborg, Carl Fredrik, 1981-, et al.
(författare)
-
BEYOND PDMS: : OFF-STOCHIOMETRY THIOL-ENE BASED SOFT LITHOGRAPHY FOR RAPID PROTOTYPING OF MICROFLUIDIC DEVICES
- 2010
-
Ingår i: 14th International Conference on Miniaturized Systems for Chemistry and Life Sciences (micro TAS 2010). - 9781618390622 ; , s. 70-72
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Konferensbidrag (refereegranskat)abstract
- We present an easy to use, rapid fabrication platform for microfluidic systems, based on micro-molding of novel thiolene based polymer formulations. The novel fabrication platform addresses major drawbacks of PDMS by allowing large freedom in material and surface properties, including: (photo)patterning of stable surface modifications, bonding without plasma treatment, rapid UV or thermal curing, variable E-modulus, minimized leaching of uncured components [1] and suppressed non-specific binding of biomolecules [2]. This process is potentially suited for both rapid prototyping in the laboratory and medium-scale commercial production, bridging the “development gap”.
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| 5. |
- Carlborg, Carl Fredrik, et al.
(författare)
-
Beyond PDMS: off-stoichiometry thiol–ene (OSTE) based soft lithography for rapid prototyping of microfluidic devices
- 2011
-
Ingår i: Lab on a Chip. - : RSC Publishing. - 1473-0197 .- 1473-0189. ; 11:18, s. 3136-3147
-
Tidskriftsartikel (refereegranskat)abstract
- In this article we introduce a novel polymer platform based on off-stoichiometry thiol–enes (OSTEs), aiming to bridge the gap between research prototyping and commercial production of microfluidic devices. The polymers are based on the versatile UV-curable thiol–ene chemistry but takes advantage of off-stoichiometry ratios to enable important features for a prototyping system, such as one-step surface modifications, tuneable mechanical properties and leakage free sealing through direct UV-bonding. The platform exhibits many similarities with PDMS, such as rapid prototyping and uncomplicated processing but can at the same time mirror the mechanical and chemical properties of both PDMS as well as commercial grade thermoplastics. The OSTE-prepolymer can be cast using standard SU-8 on silicon masters and a table-top UV-lamp, the surface modifications are precisely grafted using a stencil mask and the bonding requires only a single UV-exposure. To illustrate the potential of the material we demonstrate key concepts important in microfluidic chip fabrication such as patterned surface modifications for hydrophobic stops, pneumatic valves using UV-lamination of stiff and rubbery materials as well as micromachining of chip-to-world connectors in the OSTE-materials.
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| 6. |
- Carlborg, Carl Fredrik, et al.
(författare)
-
Biosticker : patterned microfluidic stickers for rapid integration with microarrays
- 2011
-
Ingår i: The 15th International Conference on Miniaturized Systems for Chemistry and Life Sciences (microTAS 2011). - : Chemical and Biological Microsystems Society. - 9781618395955 ; , s. 311-313
-
Konferensbidrag (refereegranskat)abstract
- We present a one-step, reversible, and biocompatible bonding method of a stiff patterned microfluidic "Biosticker", based on off-stoichiometry thiol-ene (OSTE) polymers [1], to state-of-the-art spotted microarray surfaces. The method aims at improving and simplifying the batch back-end processing of microarrays. We illustrate its ease of use in two applications: a high sensitivity flow-through protein assay; and a DNA-hybridization test. Read-out was performed in a standard highvolume array scanner, and showed excellent spot homogeneity and intensity. The Biosticker is aimed to be a plug-in for existing microarray platforms to enable faster protein assays and DNA hybridizations through mass transport optimization.
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| 7. |
- Carlborg, Carl Fredrik, et al.
(författare)
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Functional Off-Stoichiometry Thiol-ene-epoxy Thermosets Featuring Temporally Controlled Curing Stages via an UV/UV Dual Cure Process
- 2014
-
Ingår i: Journal of Polymer Science Part A. - : John Wiley & Sons. - 0887-624X .- 1099-0518. ; 52:18, s. 2604-2615
-
Tidskriftsartikel (refereegranskat)abstract
- We present a facile two-stage UV/UV activation method for the polymerization of off-stoichiometry thiol-ene-epoxy, OSTE+, networks. We show that the handling and processing of these epoxy-based resins is made easier by introducing a material with a controlled curing technique based on two steps, where the first step offers excellent processing capabilities, and the second step yields a polymer with suitable end-properties. We investigate the sequential thiol-ene and thiol-epoxy reactions during these steps by studying the mechanical properties, functional group conversion, water absorption, hydrolytic stability, and thermal stability in several different thiol-ene-epoxy formulations. Finally, we conclude that the curing stages can be separated for up to 24 h, which is promising for the usefulness of this technique in industrial applications.
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| 8. |
- Carlborg, Carl Fredrik, et al.
(författare)
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LARGE SCALE INTEGRATED 3D MICROFLUIDIC NETWORKS THROUGH HIGH YIELD FABRICATION OF VERTICAL VIAS IN PDMS
- 2010
-
Ingår i: MEMS 2010. - : IEEE conference proceedings. - 9781424457649 ; , s. 240-243
-
Konferensbidrag (refereegranskat)abstract
- This paper introduces a robust, high yield, single-step fabrication method for creating densely spaced, miniaturized out-of-plane fluidic interconnecting channels (=vias) in standard poly(dimethylsiloxane) PDMS. Unblocked vias are essential for creating 3D microfluidic networks. Previously reported methods either had low yield, because of residual membranes covering the vias after polymerization, or required complicated extra steps to remove the blocking membranes.In contrast, our method prevents the formation of residual membranes by inhibition of the polymerization on top of the protuding mold features defining the vias locations. In addition to providing unblocked vias, the inhibition also leaves a flat partially cured, sticky top surface that adheres well to other surfaces and allows self-sealing stacking of several PDMS layers. We demonstrate the new method by manufacturing a densely perforated PDMS membrane and a large scale integrated (LSI) 3D PDMS microfluidic channel network. Our method enables batch manufacturing of complex fluidic devices by speeding up and simplifying the fabrication of complex microfluidic components in standard PDMS.
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| 9. |
- Carlborg, Carl Fredrik, 1981-, et al.
(författare)
-
LOW TEMPERATURE “CLICK” WAFER BONDING OF OFF-STOICHIOMETRY THIOL-ENE (OSTE) POLYMERS TO SILICON
- 2011
-
Ingår i: 15th International Conference on Miniaturized Systems for Chemistry and Life Sciences (microTAS 2011). - 9781618395955 ; , s. 1143-1145
-
Konferensbidrag (refereegranskat)abstract
- We present a low temperature (< 37°C) wafer-scale microfluidic batch packaging process using covalent, dry bonding of offstoichiometry thiol-ene polymers (OSTE), enabling rapid, bio-compatible integration of fluidics on wafer-scale in combination with excellent polymer properties.
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| 10. |
- Carlborg, Carl Fredrik, 1981-, et al.
(författare)
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RELIABLE BATCH MANUFACTURING OF MINIATURIZED VERTICAL VIAS IN SOFT POLYMER REPLICA MOLDING
- 2007
-
Ingår i: 11th International Conference on Miniaturized Systems for Chemistry and Life Sciences (microTAS 2007). ; , s. 527-529
-
Konferensbidrag (refereegranskat)abstract
- We introduce and have successfully tested an uncomplicated polydimethylsiloxane (PDMS) compatible method for batch manufacturing vertical microfluidic interconnects via a surface inhibition of cationic photopolymerization. The yield of the maskless method is 100%. Moreover, the method enhances bond strength with subsequently laminated polymer layers.
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| 11. |
- Carlborg, Fredrik, et al.
(författare)
-
RAPID PERMANENT HYDROPHILIC AND HYDROPHOBIC PATTERNING OF POLYMER SURFACES VIA OFF-STOICHIOMETRY THIOL-ENE (OSTE) PHOTOGRAFTING
- 2012
-
Ingår i: Proceedings Micro Total Analysis Systems (muTAS) 2012. ; , s. 677-679
-
Konferensbidrag (refereegranskat)abstract
- In this work we have developed a simple and robust method to permanently pattern alternating hydrophobic and hydrophilic surfaces in off-stoichiometry thiol-ene (OSTE) polymer microchannels. By being able to tune the number of unreacted thiol surface groups of the OSTE Thiol polymers and by taking advantage of spatially photo-controlled surface grafting of methacrylate monomers we achieve defined areas with contact angles from 20° to 115° within one single channel. The surface modification remains stable after storage in air (>2 months) or water (>24h).
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| 12. |
- Decrop, Deborah, et al.
(författare)
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Single-step imprinting of femtoliter microwell arrays allows digital bioassays with attomolar limit of detection
- 2017
-
Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 9:12, s. 10418-10426
-
Tidskriftsartikel (refereegranskat)abstract
- Bead-based microwell array technology is growing as an ultrasensitive target detection tool. However, dissemination of the technology and its commercial use are hampered by current fabrication methods for hydrophilic-in-hydrophobic microwell arrays, which are either expensive or labour-intensive to manufacture, or which results in low bead seeding efficiencies. In this paper, we present a novel single-step manufacturing method for imprinting cheap and disposable hydrophilic-in-hydrophobic microwell arrays suitable for single-molecule detection. Single-step imprinting of hydrophilic-in-hydrophobic microwell arrays is made possible using an innovative surface energy replication approach by means of a hydrophobic thiol-ene polymer formulation. In this polymer, hydrophobic-moiety-containing monomers self-assemble against the hydrophobic surface of the imprinting stamp, which results in a hydrophobic replica surface after polymerization. After removing the stamp, hydrophilic wells are obtained with the well bottoms consisting of glass substrate. We demonstrate that the hydrophilic-in-hydrophobic imprinted microwell arrays enable successful and efficient self-assembly of individual water droplets and seeding of magnetic beads with loading efficiencies up to 96%. We also demonstrate the suitability of the microwell arrays for the isolation and detection of single-molecules achieving a limit of detection of 17.4 aM when performing a streptavidin-biotin binding assay. The ease of manufacturing demonstrated here is expected to allow translation of digital microwell array technology towards diagnostic applications.
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| 13. |
- Decrop, Deborah, et al.
(författare)
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Single-step manufacturing of femtoliter microwell arrays in a novel surface energy mimicking polymer
- 2015
-
Ingår i: 18th International Conference on Solid-State Sensors, Actuators and Microsystems (IEEE TRANSDUCER 2015). - : IEEE.
-
Konferensbidrag (refereegranskat)abstract
- We report a novel polymer material formulation and stamp-molding technique that enable rapid single-step manufacturing of hydrophilic-in-hydrophobic microwell arrays. We developed a modified thiol-ene-epoxy polymer (mOSTE+) formulation that mimics the surface energy of its mold during polymerization. The polymer inherits the surface energy from the mold through molecular self-assembly, in which functional monomers self-assemble at the interface between the liquid prepolymer and the mold surface. Combining this novel mOSTE+ material with a stamp-molding process leads to simultaneous surface energy mimicking and micro-structuring. This method was used to manufacture microwells with hydrophilic bottom and hydrophobic sidewall, depressed in a surrounding hydrophobic surface. The microwell arrays were successfully tested for the self-assembly of 62’000 femtoliter-droplets. Such femtoliter droplet arrays are useful for, e.g., digital ELISA and single cell/molecule analysis applications.
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| 14. |
- Ejserholm, Fredrik, et al.
(författare)
-
A polymer neural probe with tunable flexibility
- 2013
-
Ingår i: 2013 6th International IEEE/EMBS Conference on Neural Engineering (NER). - 1948-3546. - 9781467319690 ; , s. 691-694
-
Konferensbidrag (refereegranskat)abstract
- A novel polymeric material, off stoichiometry thiol-ene-epoxy (OSTE+), has been evaluated for the fabrication of neural implants. OSTE+ is easily photo-structurable and exhibits mechanical properties suitable for stable implantation of the probe into brain tissue, while being sufficiently soft at physiological temperatures to reduce living tissue damage. The facile processing of OSTE+ allows use in applications where SU-8 or polyimide currently are the materials of choice. Uniquely, OSTE+ has a Young’s modulus of 1.9 GPa at 10 °C decreasing almost two orders of magnitude to 30 MPa at 40 °C, which can be compared to the Young’s modulus of 2.1 GPa for SU-8. We show a probe, with nine gold electrode sites, implanted into 0.5% agar at 40 °C using active cooling during the implantation.
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| 15. |
- Errando-Herranz, Carlos, et al.
(författare)
-
Biocompatibility of OSTE polymers studied by cell growth experiments
- 2013
-
Ingår i: Proceedings of the 17th Int. Conf. on Miniaturized Systems for Chemistry and Life Sciences (microTAS). - Freiburg, Germany.
-
Konferensbidrag (refereegranskat)abstract
- The recently introduced OSTE polymer technology has shown very useful features for microfluidics for lab-on-a-chip applications. However, no data has yet been published on cell viability on OSTE. In this work, we study the biocompatibility of three OSTE formulations by cell growth experiments. Moreover, we investigate the effect of varying thiol excess on cell viability on OSTE surfaces. The results show poor cell viability on one OSTE formulation, and viability comparable with polystyrene on a second formulation with thiol excess below 60%. In the third formulation, we observe cell proliferation. These results are promising for cell-based assays in OSTE microfluidic devices.
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| 16. |
- Errando-Herranz, Carlos, et al.
(författare)
-
Integration of microfluidics with grating coupled silicon photonic sensors by one-step combined photopatterning and molding of OSTE
- 2013
-
Ingår i: Optics Express. - : Optical Society of America. - 1094-4087. ; 21:18, s. 21293-21298
-
Tidskriftsartikel (refereegranskat)abstract
- We present a novel integration method for packaging silicon photonic sensors with polymer microfluidics, designed to be suitable for wafer-level production methods. The method addresses the previously unmet manufacturing challenges of matching the microfluidic footprint area to that of the photonics, and of robust bonding of microfluidic layers to biofunctionalized surfaces. We demonstrate the fabrication, in a single step, of a microfluidic layer in the recently introduced OSTE polymer, and the subsequent unassisted dry bonding of the microfluidic layer to a grating coupled silicon photonic ring resonator sensor chip. The microfluidic layer features photopatterned through holes (vias) for optical fiber probing and fluid connections, as well as molded microchannels and tube connectors, and is manufactured and subsequently bonded to a silicon sensor chip in less than 10 minutes. Combining this new microfluidic packaging method with photonic waveguide surface gratings for light coupling allows matching the size scale of microfluidics to that of current silicon photonic biosensors. To demonstrate the new method, we performed successful refractive index measurements of liquid ethanol and methanol samples, using the fabricated device. The minimum required sample volume for refractive index measurement is below one nanoliter.
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| 17. |
- Errando-Herranz, Carlos, et al.
(författare)
-
Integration Of Polymer Microfluidic Channels, Vias, And Connectors With Silicon Photonic Sensors By One-Step Combined Photopatterning And Molding Of OSTE
- 2013
-
Ingår i: Proceedings of the 2013 17th International Solid-State Sensors, Actuators and Microsystems Conference (Transducers). - : IEEE conference proceedings. ; , s. 1613-1616
-
Konferensbidrag (refereegranskat)abstract
- We demonstrate a method for the fast and simple packaging of silicon sensors into a microfluidic package consisting of the recently introduced {OSTE} polymer. The microfluidic layer is first microstructured and thereafter dry-bonded to a silicon photonic sensor, in a process compatible with wafer-level production, and with the entire packaging process lasting only 10 minutes. The fluidic layer combines molded microchannels and fluidic (Luer) connectors with photopatterned through-holes (vias) for optical fiber probing and fluid connections. All the features are fabricated in a single photocuring step. We report measurements with an integrated silicon photonic {Mach-Zehnder} interferometer refractive index sensor packaged by these means.
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| 18. |
- Errando-Herranz, Carlos, et al.
(författare)
-
Integration of polymer microfluidics with silicon photonic biosensors by one-step combined photopatterning and molding of OSTE
- 2013
-
Konferensbidrag (refereegranskat)abstract
- We demonstrate a method for the fast and simple packaging of silicon sensors into a microfluidic package consisting of the recently introduced {OSTE} polymer. The microfluidic layer is first microstructured and thereafter dry-bonded to a silicon photonic sensor, in a process compatible with wafer-level production, and with the entire packaging process lasting only 10 minutes. The fluidic layer combines molded microchannels and fluidic (Luer) connectors with photopatterned through-holes (vias) for optical fiber probing and fluid connections. All the features are fabricated in a single photocuring step. We report measurements with an integrated silicon photonic {Mach-Zehnder} interferometer refractive index sensor packaged by these means.
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| 19. |
- Fan, Xuge, et al.
(författare)
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Direct observation of grain boundaries in graphene through vapor hydrofluoric acid (VHF) exposure
- 2018
-
Ingår i: Science Advances. - : American Association for the Advancement of Science. - 2375-2548. ; 4:5
-
Tidskriftsartikel (refereegranskat)abstract
- The shape and density of grain boundary defects in graphene strongly influence its electrical, mechanical, and chemical properties. However, it is difficult and elaborate to gain information about the large-area distribution of grain boundary defects in graphene. An approach is presented that allows fast visualization of the large-area distribution of grain boundary–based line defects in chemical vapor deposition graphene after transferring graphene from the original copper substrate to a silicon dioxide surface. The approach is based on exposing graphene to vapor hydrofluoric acid (VHF), causing partial etching of the silicon dioxide underneath the graphene as VHF diffuses through graphene defects. The defects can then be identified using optical microscopy, scanning electron microscopy, or Raman spectroscopy. The methodology enables simple evaluation of the grain sizes in polycrystalline graphene and can therefore be a valuable procedure for optimizing graphene synthesis processes.
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| 20. |
- Fischer, Andreas C., et al.
(författare)
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Fabrication of high aspect ratio through silicon vias (TSVs) by magnetic assembly of nickel wires
- 2011
-
Ingår i: Micro Electro Mechanical Systems (MEMS), 2011 IEEE 24th International Conference on. - : IEEE. - 9781424496327 ; , s. 37-40
-
Konferensbidrag (refereegranskat)abstract
- Three-dimensional (3D) integration of electronics and/or MEMS-based transducers is an emerging technology that vertically interconnects stacked dies using through silicon vias (TSVs). They enable the realization of devices with shorter signal lengths, smaller packages and lower parasitic capacitances, which can result in higher performance and lower costs of the system. This paper presents a novel low-cost fabrication technique for solid metal-filled TSVs using nickel wires as conductive path. The wires are placed in the via hole of a silicon wafer by magnetic self-assembly. This metal filling technique enables through-wafer vias with high aspect ratios and potentially eliminates characteristic cost drivers of the TSV production such as metallization processes, wafer thinning and general issues associated with thin-wafer handling.
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| 21. |
- Fischer, Andreas C., 1982-, et al.
(författare)
-
high aspect ratio tsvs fabricated by magnetic self-assembly of gold-coated nickel wires
- 2012
-
Ingår i: Electronic Components and Technology Conference (ECTC), 2012 IEEE 62nd. - : IEEE conference proceedings. - 9781467319652 ; , s. 541-547
-
Konferensbidrag (refereegranskat)abstract
- Three-dimensional (3D) integration is an emerging technologythat vertically interconnects stacked dies of electronics and/orMEMS-based transducers using through silicon vias (TSVs).TSVs enable the realization of devices with shorter signal lengths,smaller packages and lower parasitic capacitances, which can resultin higher performance and lower costs of the system. Inthis paper we demonstrate a new manufacturing technology forhigh-aspect ratio (> 8) through silicon metal vias using magneticself-assembly of gold-coated nickel rods inside etched throughsilicon-via holes. The presented TSV fabrication technique enablesthrough-wafer vias with high aspect ratios and superior electricalcharacteristics. This technique eliminates common issues inTSV fabrication using conventional approaches, such as the metaldeposition and via insulation and hence it has the potential to reducesignificantly the production costs of high-aspect ratio stateof-the-art TSVs for e.g. interposer, MEMS and RF applications.
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| 22. |
- Fischer, Andreas C., 1982-, et al.
(författare)
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Very high aspect ratio through-silicon vias (TSVs) fabricated using automated magnetic assembly of nickel wires
- 2012
-
Ingår i: Journal of Micromechanics and Microengineering. - : Institute of Physics (IOP). - 0960-1317 .- 1361-6439. ; 22:10, s. 105001-
-
Tidskriftsartikel (refereegranskat)abstract
- Through-silicon via (TSV) technology enables 3D-integrated devices with higher performance and lower cost as compared to 2D-integrated systems. This is mainly due to smaller dimensions of the package and shorter internal signal lengths with lower capacitive, resistive and inductive parasitics. This paper presents a novel low-cost fabrication technique for metal-filled TSVs with very high aspect ratios (>20). Nickel wires are placed in via holes of a silicon wafer by an automated magnetic assembly process and are used as a conductive path of the TSV. This metal filling technique enables the reliable fabrication of through-wafer vias with very high aspect ratios and potentially eliminates characteristic cost drivers in the TSV production such as advanced metallization processes, wafer thinning and general issues associated with thin-wafer handling.
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| 23. |
- Forsberg, Fredrik, et al.
(författare)
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A Comparative study of the bonding energy in adhesive wafer bonding
- 2013
-
Ingår i: Journal of Micromechanics and Microengineering. - : IOP Publishing. - 0960-1317 .- 1361-6439. ; 23:8, s. 1-7
-
Tidskriftsartikel (refereegranskat)abstract
- Adhesion energies are determined for three different polymers currently used in adhesive wafer bonding of silicon wafers. The adhesion energies of the polymer off-stoichiometry thiol-ene-epoxy OSTE+ and the nano-imprint resist mr-I 9150XP are determined. The results are compared to the adhesion energies of wafers bonded with benzocyclobutene, both with and without adhesion promoter. The adhesion energies of the bonds are studied by blister tests, consisting of delaminating silicon lids bonded to silicon dies with etched circular cavities, using compressed nitrogen gas. The critical pressure needed for delamination is converted into an estimate of the bond adhesion energy. The fabrication of test dies and the evaluation method are described in detail. The mean bond energies of OSTE+ were determined to be 2.1 and 20 J m(-2) depending on the choice of the epoxy used. A mean bond energy of 1.5 J m(-2) was measured for mr-I 9150XP.
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| 24. |
- Forsberg, Fredrik, 1980-, et al.
(författare)
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Batch Transfer of Radially Expanded Die Arrays for Heterogeneous Integration Using Different Wafer Sizes
- 2012
-
Ingår i: Journal of microelectromechanical systems. - 1057-7157 .- 1941-0158. ; 21:5, s. 1077-1083
-
Tidskriftsartikel (refereegranskat)abstract
- This paper reports on the realization of a novel method for batch transfer of multiple separate dies from a smaller substrate onto a larger wafer substrate by using a standard matrix expander in combination with an elastic dicing tape and adhesive wafer bonding. We demonstrate the expansion and transfer of about 30 000 dies from a 100-mm wafer format to a 200-mm wafer. Furthermore, multiple expansions of 100-mm wafers diced into 60 000 dies are evaluated to determine the position accuracy between different expansions. Fabrication, evaluation method, and results are presented.
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| 25. |
- Forsberg, Fredrik, et al.
(författare)
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HETEROGENEOUS INTEGRATION METHOD FOR TRANSFER OFEXPANDED DIE MATRICES TO LARGE FORMAT WAFERS USINGAN EXPANDABLE TAPE
- 2012
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper reports on the realization of a novel method for batch transfer of multiple separate dies from a smallersubstrate onto a larger wafer substrate by using a standard matrix expander in combination with adhesive waferbonding and an elastic dice tape. We demonstrate the expansion and transfer of about 30000 chips from a 100mm wafer to a 200 mm wafer with a 22 μm standard deviation of positioning accuracy.
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| 26. |
- Forsberg, Fredrik, 1980-, et al.
(författare)
-
Low temperature adhesive wafer bonding using OSTE(+) for heterogeneous 3D MEMS integration
- 2013
-
Ingår i: Micro Electro Mechanical Systems (MEMS), 2013 IEEE 26th International Conference on. - : IEEE conference proceedings. - 9781467356541 ; , s. 342-346
-
Konferensbidrag (refereegranskat)abstract
- We demonstrate, for the first time, the use of off stoichiometry thiolene-epoxy, OSTE(+) for adhesive wafer bonding. The dual cure system, with an initial UV-curing step followed by a second thermal cure, allows for high bond strength and potentially high quality material interfaces. We show that cured OSTE(+) is easily removed in oxygen plasma and that the characteristics of OSTE(+) make it a potential candidate for use in heterogeneous 3D MEMS integration. Furthermore, we show how the bond energies of wafers bonded with OSTE(+) adhesive compares with the bond energies of wafers bonded with Cyclotene 3022-46 (BCB) and mr-I 9150XP nanoimprint resist.
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| 27. |
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| 28. |
- Guo, Maoxiang, et al.
(författare)
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LONG-TERM STORAGE OF NANOLITRE AND PICOLITRE LIQUID VOLUMES IN POLYMER MICROFLUIDIC DEVICES
- 2015
-
Ingår i: the 19th International Conference on Miniaturized Systems for Chemistry and Life Sciences (Micro TAS). - : The Chemical and Biological Microsystems Society. - 9780979806483 ; , s. 1386-1388
-
Konferensbidrag (refereegranskat)abstract
- We introduce uncomplicated nanolitre (23 nL) and picolitre (3.5 pL) liquid volume encapsulation in Off-Stoichiometry Thiol-Ene-Epoxy polymer (OSTEmerTM322) wells using spontaneous room- temperature bonding of gold films to thiol and thioether groups present on the surface of the polymer for leak free sealing. First, we show liquid encapsulation within nL, and pL polymer wells by utilizing 100 nm thin Au-film transfer-bonding onto intermediately cured, and micropatterned OSTEmerTM322. This approach yielded 3 magnitude orders smaller liquid volume encapsulation than previously reported. Secondly, we show that encapsulated liquid can be stored for >116 h. Finally, we demonstrate encapsulated liquid release by thermopneumatic bursting. We conclude that OSTEmerTM322 is excellent for metal-film sealant integration in polymer microfluidic devices.
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| 29. |
- Gylfason, Kristinn B., 1978-, et al.
(författare)
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Integration of polymer based microfluidics with silicon photonics for biosensing applications
- 2015
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- We present a novel integration method for packaging silicon photonic sensors with polymer microfluidics, designed to be suitable for wafer-level production. The method addresses the previously unmet manufacturing challenges of matching the microfluidic footprint area to that of the photonics, and of robust bonding of microfluidic layers to biofunctionalized surfaces. We demonstrate the fabrication, in a single step, of a microfluidic layer in the recently introduced OSTE polymer, and the subsequent unassisted dry bonding of the microfluidic layer to a grating coupled silicon photonic ring resonator sensor chip. The microfluidic layer features photopatterned through holes (vias) for optical fiber probing and fluid connections, as well as molded microchannels and tube connectors, and is manufactured and subsequently bonded to a silicon sensor chip in less than 10 minutes. Combining this new microfluidic packaging method with photonic waveguide surface gratings for light couplin g allows matching the size scale of microfluidics to that of current silicon photonic biosensors.
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| 30. |
- Hansson, Jonas, 1983-, et al.
(författare)
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Direct Lithography of Rubbery OSTE+ Polymer
- 2014
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Ingår i: Proceedings 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS2014). - : 14CBMS. - 9780979806476 ; , s. 123-125
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Konferensbidrag (refereegranskat)abstract
- We present a Rubbery, Off-Stoichiometric Thiol-Ene-epoxy (OSTE+) polymer for direct lithography manufacturing, demonstrate its use in pneumatic pinch microvalves for lab-on-chip applications, test the lithography process achieving pillars of aspect-ratios (a.r.) 1:8, and characterize it’s surface as hydrophilic.
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| 31. |
- Hansson, Jonas, et al.
(författare)
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Inertial microfluidics in parallel channels for high-throughput applications
- 2012
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Ingår i: Lab on a Chip. - : Royal Society of Chemistry. - 1473-0197 .- 1473-0189. ; 12:22, s. 4644-4650
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Tidskriftsartikel (refereegranskat)abstract
- Passive particle focusing based on inertial microfluidics was recently introduced as a high-throughput alternative to active focusing methods that require an external force-field to manipulate particles. In this study, we introduce inertial microfluidics in flows through straight, multiple parallel channels. The scalable, single inlet and two outlet, parallel channel system is enabled by a novel, high-density 3D PDMS microchannel manufacturing technology, mediated via a targeted inhibition of PDMS polymerization. Using single channels, we first demonstrate how randomly distributed particles can be focused into the centre position of the channel in flows through low aspect ratio channels and can be effectively fractionated. As a proof of principle, continuous focusing and filtration of 10 μm particles from a suspension mixture using 4- and 16-parallel-channel devices with a single inlet and two outlets are demonstrated. A filtration efficiency of 95-97% was achieved at throughputs several orders of magnitude higher than previously shown for flows through straight channels. The scalable and low-footprint focusing device requiring neither external force fields nor mechanical parts to operate is readily applicable for high-throughput focusing and filtration applications as a stand-alone device or integrated with lab-on-a-chip systems.
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| 32. |
- Hansson, Jonas, et al.
(författare)
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Inertial Particle Focusing In Parallel Microfluidic Channels For High-Throughput Filtration
- 2011
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Ingår i: 16th International Solid-State Sensors, Actuators and Microsystems Conference (TRANSDUCERS), 2011. - : IEEE conference proceedings. - 9781457701573 ; , s. 1777-1780
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Konferensbidrag (refereegranskat)abstract
- In this study, we introduce inertial microfluidics in straight, parallel channels for high-throughput particle filtration. We show that particles flowing through low aspect ratio rectangular microchannels can be focused into four particle streams, distributed at the centers of each wall face, or into two particle streams, at the centers of the longest channel walls, depending on the particles' size. For high-throughput filtration, we fabricated scalable, single inlet and two outlet, parallel channel microdevices, using a high-density 3D microfluidic PDMS channel manufacturing technology, in a design that allows for easy integration with other downstream on-chip functions we recently described. We demonstrate filtration of 24 μm particles from a suspension mixture in a microdevice with four parallel channels. The filtration efficiency at a non-optimized flow rate of 0.8 ml/min was 82%.
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| 33. |
- Hansson, Jonas, et al.
(författare)
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Leak-tight vertical membrane microvalves
- 2016
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Ingår i: Lab on a Chip. - : Royal Society of Chemistry. - 1473-0197 .- 1473-0189. ; 16:8, s. 1439-1446
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Tidskriftsartikel (refereegranskat)abstract
- Pneumatic microvalves are fundamental control components in a large range of microfluidic applications. Their key performance parameters are small size, i.e. occupying a minimum of microfluidic real estate, low flow resistance in the open state, and leak-tight closing at limited control pressures. In this work we present the successful design, realization and evaluation of the first leak-tight, vertical membrane, pneumatic microvalves. The realization of the vertical membrane microvalves is enabled by a novel dual-sided molding method for microstructuring monolithic 3D microfluidic networks in PDMS in a single step, eliminating the need for layer-to-layer alignment during bonding. We demonstrate minimum lateral device features down to 20-30 mu m in size, and vertical via density of similar to 30000 per cm(2), which provides significant gains in chip real estate compared to previously reported PDMS manufacturing methods. In contrast to horizontal membrane microvalves, there are no manufacturing restrictions on the cross-sectional geometry of the flow channel of the vertical membrane microvalves. This allows tuning the design towards lower closing pressure or lower open state flow resistance compared to those of horizontal membrane microvalves.
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| 34. |
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| 35. |
- Hansson, Jonas, et al.
(författare)
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Low gas permeable and non-absorbent rubbery OSTE+ for pneumatic microvalves
- 2014
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Ingår i: Proceedings of the 27th IEEE International Conference on Micro Electro Mechanical Systems (MEMS 2014). - : IEEE conference proceedings. - 9781479935093 ; , s. 987-990
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Konferensbidrag (refereegranskat)abstract
- In this paper we introduce a new polymer for use in microfluidic applications, based on the off-stoichiometric thiol–ene-epoxy (OSTE+) polymer system, but with rubbery properties. We characterize and benchmark the new polymer against PDMS. We demonstrate that Rubbery OSTE+: has more than 90% lower permeability to gases compared to PDMS, has little to no absorption of dissolved molecules, can be layer bonded in room temperature without the need for adhesives or plasma treatment, can be structured by standard micro-molding manufacturing, and shows similar performance as PDMS for pneumatic microvalves, albeit allowing handling of larger pressure.
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| 36. |
- Hansson, Jonas, et al.
(författare)
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Synthetic microfluidic paper
- 2015
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Ingår i: Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS). - : IEEE conference proceedings. ; , s. 10-13
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Konferensbidrag (refereegranskat)abstract
- We introduce a polymer synthetic microfluidic paper for lateral flow devices. The aim is to combine the high surface area of paper, or nitrocellulose, with the repeatability, controlled structure, and transparency of polymer micropillars. Our synthetic paper consists of a dense, high aspect ratio array of transparent pillars that are slanted and mechanically interlocked. We describe the manufacturing using multidirectional UV lithography and demonstrate successful capillary pumping of whole blood.
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| 37. |
- Hansson, Jonas, et al.
(författare)
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Synthetic microfluidic paper allows controlled receptor positioning and improved readout signal intensity in lateral flow assays
- 2015
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Ingår i: MicroTAS 2015 - 19th International Conference on Miniaturized Systems for Chemistry and Life Sciences. - : Chemical and Biological Microsystems Society. - 9780979806483 ; , s. 284-286
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Konferensbidrag (refereegranskat)abstract
- Synthetic Microfluidic Paper consists of slanted and interlocked polymer micropillars and can be used as a porous substrate in microfluidics and lateral flow assays. We here demonstrate single step manufacturing of multiple Synthetic Microfluidic Paper densities in the same device, and passive alignment of liquid spots in denser substrate regions, regardless of spotting position, allowing increased control of receptor positioning for lateral flow assays. We further demonstrate that the transparency of Synthetic Microfluidic Paper allows increasing readout signal intensity with increasing substrate thickness, to a value 3 times larger compared to nitrocellulose substrates.
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| 38. |
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| 39. |
- Hansson, Jonas, 1983-, et al.
(författare)
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Synthetic paper
- 2017
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Patent (populärvet., debatt m.m.)abstract
- A synthetic paper is manufactured with a method comprising the steps of: a) providing at least two types of pho to-polymerizable monomers, b) exposing the volume to a three-dimensional light pattern to induce a polymerization reaction, and c) removing uncured monomer to create an open microstructure. The volume comprises at least one monomer comprising at least two thiol groups and at least one monomer comprising at least two carbon-carbon double bonds, where the ratio (r1) between the number of thiol groups and the number of carbon-carbon double bonds fulfils one of: 0.5≦r1≦0.9 and 1.1≦r1≦2. One advantage is that off stoichiometry creates an edge effect giving better defined boundaries between exposed and unexposed parts in the volume and giving a possibility to create thinner micro pillars. Another advantage is that it is easy to bind molecules to the surface to obtain desired surface properties.
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| 40. |
- Hansson, Jonas, et al.
(författare)
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Vertical membrane microvalves in PDMS
- 2015
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Ingår i: 2015 28th IEEE International Conference on Micro Electro Mechanical Systems (MEMS). - : IEEE. ; , s. 563-565
-
Konferensbidrag (refereegranskat)abstract
- We present the design, realization and evaluation of the first leak-tight vertical membrane pneumatic microvalve. The design freedom in the vertical valve configuration allows for a flow throughput per footprint area that is increased two orders of magnitude compared to horizontal membrane microvalves.
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| 41. |
- Haraldsson, Klas Tommy, et al.
(författare)
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3D Polymeric Microfluidic Device Fabrication via Contact Liquid Photolithographic Polymerization (CLiPP)
- 2006
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier BV. - 0925-4005 .- 1873-3077. ; 113:1, s. 454-460
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Tidskriftsartikel (refereegranskat)abstract
- In this contribution, a new method for the fabrication of complex polymeric microfluidic devices is presented. The technology, contact liquid photolithographic polymerization (CLIPP). overcomes many of the draw backs associated kith other rapid prototyping schemes, such as limited materials choices and time-consuming microassembly protocols. CUPP shares many traits with other photolithographic methods, but three distinct features: (i) liquid photoresists in contact with the photomask. (ii) readily removed sacrificial Materials. and (iii) living radical processes, enable multiple polymeric chemistries and mechanical properties while simultaneously enabling facile fabrication of 3D geometries and surface chemistry control. This contribution details fabrication techniques and methods for the fabrication of high aspect ratio posts covalently bonded to a polymeric substrate, an array of independently stacked bars on top of perpendicular bars, multiple undercut structures fabricated simultaneously, and a complex 3D geometry with intertwined channels.
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| 42. |
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| 43. |
- Haraldsson, Klas Tommy, 1968-
(författare)
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Fabrication of polymeric microfluidic devices via photocurable liquid monomers
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Microfluidic devices have long been considered an ideal tool for rapid and inexpensive chemical analysis and reactions in areas ranging from point-of-care health to national security applications. However, fabricating microfluidic devices is time consuming, difficult and above all expensive. In commercial applications many thousand units need to be sold before the development costs are recovered. The problem is compounded since most microfluidic devices do not have generalized architectures which means that each end use requires a specialized design. The microfluidics marketplace can therefore be seen as being composed of 1000’s of niche markets. To address development costs, there is clearly a need for a versatile technology that can be used for many different applications and that enables rapid testing and optimization of new designs. This work describes such a technology: Contact Liquid Photolithographic Polymerization (CLiPP). The thesis consists of two parts: polymerization kinetics and the fabrication of polymeric microfluidic devices via CLiPP. The photopolymerization kinetics is evaluated for a number of monomer types, and the results are used to assess their suitability in the CLiPP process. Vinyl ether/maleate photoinitiated copolymerization is examined in detail. It is shown that the polymerization kinetics is dramatically influenced by the availability of easily abstractable hydrogens The presence of α-hydrogens adjacent to the vinyl ether functional group reduces the polymerization rate and the dependence of the polymerization rate as a function of initiation rate. Also, photoinitiated acrylate and methacrylate polymerization kinetics are presented. The kinetics results in these three monomer types are used to explain the different patterning properties of the monomer functionalities used in the CLiPP process, in which acrylates show enhanced patterning properties compared to methacrylates. The polymerization kinetics is studied with traditional tools and methods: photo Differential Scanning Calorimetry (photo-DSC), photo Fourier Transform Real Time Infrared Spectroscopy (photo-RTIR), and photo Real Time Electron Paramagnetic Spectroscopy (ESR). The microfluidic fabrication is performed via both in-house fabricated and commercially available CLiPP-specific hardware. The patterning qualities of the structures are evaluated via Scanning Electron Microscopy (SEM) and Optical Microscopy. The finished devices are used in their intended environment and evaluated in suitable manners to assess their utility. In this thesis, the development and design of specialized CLiPP fabrication machines, fabrication techniques and resulting microfluidic device features are presented anddiscussed. It is shown that the CLiPP scheme enables features such as 3 dimensional (3D) capabilities for minimized device footprints, a very large number of polymeric materials for optimized device components as well as facile integration of prefabricated components. Also, covalent layer adhesion and permanent surface modifications via living radical processes are demonstrated. These capabilities are exemplified in a number of examples that range from a 3D fluidic channel maze with separated fluidic streams and a device with independently moveable parts to a device constructed from multiple polymeric materials and devices with permanently modified surfaces, Also, batch processing capabilities are shown through fabrication of 400 identical undercut microstructures. Rapid and inexpensive design evaluations, multiple materials capabilities and the ability to seamlessly incorporate prefabricated microstructures of the CLiPP process strongly encourages continued method development. The future work that remains to be addressed is divided into two parts. First, to enable novel research devices, new polymer materials with enhanced mechanical and surface properties must be developed. Also, integration of prefabricated microstructures such as sensors and actuators has to be incorporated in a reproducible and rational manner. Secondly, to enable device mass fabrication, new automated equipment is to be developed in order to utilize the full batch processing potential of CLiPP.
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| 44. |
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| 45. |
- Haraldsson, Klas Tommy, et al.
(författare)
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The Effects of Abstractable Hydrogen in Radical Photopolymerization of Maleate/Vinyl Ether Monomers Studied with EPR and Photo-RTIR
- 2010
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Ingår i: Journal of Polymer Science Part A. - : Wiley. - 0887-624X .- 1099-0518. ; 48:13, s. 2810-2816
-
Tidskriftsartikel (refereegranskat)abstract
- In this contribution, the influence of abstractable hydrogen on the kinetics of photopolymerized vinyl ether/maleate monomer formulations is reported. The effects of chain transfer on the polymerization rate were studied with photo real-time Infra Red (IR) for formulations composed of equimolar amounts of diethyl (DEMA) and three different vinyl ethers; methyl hexyl vinyl ether where the abstractable hydrogens adjacent to the vinyl functionality have been replaced with methyl groups, ethyl hexyl vinyl ether (EHVE) which has two easily abstractable alpha-hydrogens and triethylene glycol methyl vinyl ether (TEGMVE), which has several abstractable hydrogens. Four conclusions are drawn from these studies: (i) the vinyl ether/maleate kinetics differs significantly from the classical expression R-p = KI0.5, with recorded exponential factors of 0.84 +/- 0.04 in the absence of easily abstractable hydrogens; (ii) the presence of abstractable hydrogens significantly changes the kinetics of vinyl ether/maleate polymerizations with recorded exponential factors of 0.55 +/- 0.04 for EHVE/DEMA and 0.70 +/- 0.04 for TEGMVE/DEMA; (iii) the presence of easily abstractable hydrogens leads to a preferential consumption of maleates; and (iv) electron paramagnetic resonance studies show that vinyloxy-like radicals constitute the majority of the radicals in the systems with easily abstractable hydrogens.
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| 46. |
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| 47. |
- Haraldsson, Tommy, et al.
(författare)
-
OSTE - a novel polymer system developed for Lab-on-Chip
- 2014
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Ingår i: Proceedings of SPIE Volume 8976. - : SPIE - International Society for Optical Engineering. - 9780819498892 ; , s. 897608-
-
Konferensbidrag (refereegranskat)abstract
- OSTE polymer has the aim to address today's dissemination gap between successful lab-on-chip research and the healthcare setting. We have formulated and demonstrated a novel, superior, polymer system, OSTE, and its manufacturing platform, which is based on the mixture of three monomers: thiols, -enes and epoxies. The uniqueness of the OSTE approach stems from the curing in two distinct steps: after the first cure, an intermediate polymer is formed which is ideally suited for surface modifications and bonding; after the second cure we obtain an inert and robust polymer. Our vision is that OSTE has the potential to form a de-facto standard for research and development of high performance labs-on-chip in academia and industry.
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| 48. |
- Hill, Daniel, et al.
(författare)
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Microfluidic and Transducer Technologies for Lab on a Chip Applications
- 2010
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Ingår i: 2010 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC). - : IEEE conference proceedings. - 9781424441242 ; , s. 305-307
-
Konferensbidrag (refereegranskat)abstract
- Point-of-care diagnostic devices typically require six distinct qualities: they must deliver at least the same sensitivity and selectivity, and for a cost per assay no greater than that of today's central lab technologies, deliver results in a short period of time (<15 min at GP; <2h in hospital), be portable or at least small in scale, and require no or extremely little sample preparation. State-of-the-art devices deliver information of several markers in the same measurement.
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| 49. |
- Hillmering, Mikael, 1982-
(författare)
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Polymer microfluidic systems for samplepreparation for bacterial detection
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Sepsis, caused by blood stream infection, is a very serious health condition thatrequires immediate treatment using antibiotics to increase the chances for patientsurvival. A high prevalence of antibiotic resistance among infected patients requiresstrong and toxic antibiotics to ensure effective treatment. A rapid diagnostic devicefor detection of antibiotic resistance genes in pathogens in patient blood would enablean early change to accurate and less toxic antibiotics. Although there is a pressingneed for such devices, rapid diagnostic tests for sepsis do not yet exist.In this thesis, novel advances in microfabrication and lab-on-a-chip devices arepresented. The overall goal is to develop microfluidics and lab-on-a-chip systems forrapid sepsis diagnostics. To approach this goal, novel manufacturing techniques formicrofluidics systems and novel lab-on-a-chip devices for sample preparation havebeen developed.Two key problems for analysis of blood stream infection samples are that lowconcentrations of bacteria are typically present in the blood, and that separation ofbacteria from blood cells is difficult. To ensure that a sufficient amount of bacteria isextracted, large sample volumes need to be processed, and bacteria need to be isolatedwith high efficiency. In this thesis, a particle filter based on inertial microfluidicsenabling high processing flow rates and integration with up- and downstream processesis presented.Another important function for diagnostic lab-on-a-chip devices is DNA amplificationusing polymerase chain reaction (PCR). A common source of failure for PCRon-chip is the formation of bubbles during the analysis. In this thesis, a PCR-on-chipsystem with active degassing enabling fast bubble removal through a semipermeablemembrane is presented.Several novel microfabrication methods were developed. Novel fabrication techniquesusing the polymer PDMS that enable manufacturing of complex lab-on-a-chipdevices containing 3D fluidic networks and fragile structures are presented. Also,a mechanism leading to increased accuracy in photopatterning in thiol-enes, whichenables rapid prototyping of microfluidic devices, is described. Finally, a novel flexibleand gas-tight polymer formulation for microfabrication is presented: rubbery OSTE+.Together, the described achievements lead to improved manufacturing methodsand performances of lab-on-a-chip devices, and may facilitate future development ofdiagnostic devices.
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| 50. |
- Huang, Jing, 1987-, et al.
(författare)
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Triplex Glass Laminates with Silicon Quantum Dots for Luminescent Solar Concentrators
- 2020
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Ingår i: Solar RRL. - : Wiley. - 2367-198X. ; 4:9
-
Tidskriftsartikel (refereegranskat)abstract
- Luminescent solar concentrator (LSC) is a promising technology to integrate semitransparent photovoltaic (PV) systems into modern buildings and vehicles. Silicon quantum dots (QDs) are good candidates as fluorophores in LSCs, due to the absence of overlap between absorption and emission spectra, high photoluminescence quantum yield (PLQY), good stability, nontoxicity, and element abundance. Herein, LSCs based on Si QDs/polymer nanocomposites are fabricated in a triplex glass configuration. A special polymer matrix (off-stoichiometric thiol-ene, OSTE) is used, which improves Si nanocrystal quantum yield. Herein, a comprehensive investigation to improve the performance of LSCs by exploring different strategies under the guidance of a theoretical description is conducted. Among these strategies, the systematical enhancement of PLQY of the nanocomposite is achieved by tuning the thiol/allyl group ratio in the OSTE matrix. In addition, ligand selection and loading optimization for QDs reduce the total scattering loss in the device. Finally, an optical power efficiency of 7.9% is achieved for an optimized LSC prototype (9 x 9 x 0.6 cm(3), transmittance approximate to 62% at 500 nm) based on Si QDs/OSTE nanocomposite, which shows good potential of this material system in LSC fabrication.
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