| 1. |
- Andersson, Malte, 1941, et al.
(författare)
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”Minskande befolkning är inte problemet”
- 2020
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Ingår i: Dagens Nyheter. ; :1 augusti, DN-debatt
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Nätverket Population Matters Sweden: En uppmärksammad studie i The Lancet pekar mot en lägre befolkningsökning i världen än tidigare prognoser. Men en miljard människor till är fortfarande långt över vad jorden klarar. Befolkningstrenden måste snarare vända neråt, och det kräver åtgärder för att stärka kvinnors rättigheter världen över.
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| 2. |
- Forsen, E, et al.
(författare)
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Dry release of suspended nanostructures
- 2004
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Ingår i: Microelectronic Engineering. - 1873-5568. ; 73-74, s. 487-490
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Tidskriftsartikel (refereegranskat)abstract
- A dry release method for fabrication of suspended nanostructures is presented. The technique has been combined with an anti-stiction treatment for fabrication of nanocantilever based nanoelectromechanical systems (NEMS). The process combines a dry release method, using a supporting layer of photoresist which is removed using oxygen ashing in a reactive ion etcher (RIE), with CHF3 plasma induced deposition of an fluorocarbon (FC) film acting as an antistiction coating. All in a single RIE sequence. The dry release process is contamination free and batch process compatible. Furthermore, the technique enables long time storage and transportation of produced devices without the risk of stiction. By combining the dry release method with a plasma deposited anti-stiction coating both fabrication induced stiction, which is mainly caused by capillary forces originating from the dehydration of meniscuses formed between suspended structures and the substrate during processing, as well as in-use stiction, occurring during mechanical operation of the system, are avoided. (C) 2004 Elsevier B.V. All rights reserved.
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| 3. |
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| 4. |
- Forsen, E, et al.
(författare)
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Fabrication of cantilever based mass sensors integrated with CMOS using direct write laser lithography on resist
- 2004
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 15:10, s. 628-633
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Tidskriftsartikel (refereegranskat)abstract
- A CMOS compatible direct write laser lithography technique has been developed for cantilever fabrication on pre-fabricated standard CMOS. We have developed cantilever based sensors for mass measurements in vacuum and air. The cantilever is actuated into lateral vibration by electrostatic excitation and the resonant frequency is detected by capacitive readout. The device is integrated on standard CMOS circuitry. In the work a new direct write laser lithography (DWL) technique is introduced. This laser lithography technique is based on direct laser writing on substrates coated with a resist bi-layer consisting of poly(methyl methacrylate) (PMMA) on lift-off resist (LOR). Laser writing evaporates the PMMA, exposing the LOR. A resist solvent is used to transfer the pattern down to the substrate. Metal lift-off followed by reactive ion etching is used for patterning the structural poly-Si layer in the CMOS. The developed laser lithography technique is compatible with resist exposure techniques such as electron beam lithography. We demonstrate the fabrication of sub-micrometre wide suspended cantilevers as well as metal lift-off with feature line widths down to approximately 500 nm.
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| 5. |
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| 6. |
- Forsen, E, et al.
(författare)
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Laser lithography on resist bi-layer for nanoelectromechanical systems prototyping
- 2004
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Ingår i: Microelectronic Engineering. - 1873-5568. ; 73-74, s. 491-495
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Tidskriftsartikel (refereegranskat)abstract
- We present a laser lithography technique based on lift-off, for fast and flexible prototyping of micro and nanoelectromechanical systems (MEMS/NEMS). The technique is based on direct laser writing on substrates coated with a resist bi-layer consisting of polymethyl methacrylate (PMMA) on lift-off resist (LOR). Laser writing melts and evaporates the PMMA exposing the LOR. Oxygen ashing removes PMMA residues within the lithography pattern. A resist solvent is used to transfer the pattern down to the substrate. The LOR is dissolved isotropically while the PMMA is unaffected by the solvent, hence creating an undercut profile. After metal evaporation a two-step lift-off process prevents metal flakes from adhering to the surface. First, warm acetone dissolves the PMMA and lifts off the metal layer, then warm Remover PG removes the LOR and any remaining metal. Metal structures with line widths down to 600 nm and dots with 600 mn diameters are presented. (C) 2004 Elsevier B.V. All rights reserved.
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| 7. |
- Forsen, E, et al.
(författare)
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Ultrasensitive mass sensor fully integrated with complementary metal-oxide-semiconductor circuitry
- 2005
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 87:4
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Tidskriftsartikel (refereegranskat)abstract
- Nanomechanical resonators have been monolithically integrated on preprocessed complementary metal-oxide-semiconductor (CMOS) chips. Fabricated resonator systems have been designed to have resonance frequencies up to 1.5 MHz. The systems have been characterized in ambient air and vacuum conditions and display ultrasensitive mass detection in air. A mass sensitivity of 4 ag/Hz has been determined in air by placing a single glycerine drop, having a measured weight of 57 fg, at the apex of a cantilever and subsequently measuring a frequency shift of 14.8 kHz. CMOS integration enables electrostatic excitation, capacitive detection, and amplification of the resonance signal directly on the chip.
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| 8. |
- Ghatnekar-Nilsson, Sara, et al.
(författare)
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Resonators with integrated CMOS circuitry for mass sensing applications, fabricated by electron beam lithography
- 2005
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 16:1, s. 98-102
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Tidskriftsartikel (refereegranskat)abstract
- A resonator system has been fabricated directly on a pre-processed CMOS chip. The system is to be used for high sensitivity mass sensing applications in air and vacuum. The resonator system, corresponding of a cantilever and structures for electrostatic actuation and capacitive read-out, have been defined by electron beam lithography on top of a charge and radiation sensitive CMOS layer in predefined areas as a post-process step. This has been accomplished without affecting the electronic properties of the pre-processed CMOS circuits. The subsequent etching steps to fully release the cantilevers have been obtained without stiction of the cantilevers to the substrate. Cantilevers are driven at their mechanical resonance in a lateral mode, and the frequency is monitored by capacitive read-out on the chip. CMOS integration enables signal detection directly on the chip, which radically decreases the parasitic capacitances. Consequently, low-noise electrical measurements with a very high mass sensitivity are obtained. Fabricated resonator systems were characterized to have resonance frequencies of approximately 1.49 MHz, which is in good agreement with a theoretical estimation of 1.41 MHz. The theoretical mass resolution, partial derivativem/partial derivativef, is approximately 17 ag Hz(-1) using a Young modulus value of 160 GPa.
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| 9. |
- Hakonen, Aron, 1970, et al.
(författare)
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Detection of nerve gases using surface-enhanced Raman scattering substrates with high droplet adhesion
- 2016
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Ingår i: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3372 .- 2040-3364. ; 8:3, s. 1305-1308
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Tidskriftsartikel (refereegranskat)abstract
- Threats from chemical warfare agents, commonly known as nerve gases, constitute a serious security issue of increasing global concern because of surging terrorist activity worldwide. However, nerve gases are difficult to detect using current analytical tools and outside dedicated laboratories. Here we demonstrate that surface-enhanced Raman scattering (SERS) can be used for sensitive detection of femtomol quantities of two nerve gases, VX and Tabun, using a handheld Raman device and SERS substrates consisting of flexible gold-covered Si nanopillars. The substrate surface exhibits high droplet adhesion and nanopillar clustering due to elasto-capillary forces, resulting in enrichment of target molecules in plasmonic hot-spots with high Raman enhancement. The results may pave the way for strategic life-saving SERS detection of chemical warfare agents in the field.
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| 10. |
- Juhlin, Lars, et al.
(författare)
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Selective surface-enhanced Raman scattering detection of Tabun, VX and Cyclosarin nerve agents using 4-pyridine amide oxime functionalized gold nanopillars
- 2020
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Ingår i: Talanta. - : Elsevier BV. - 0039-9140 .- 1873-3573. ; 211
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Tidskriftsartikel (refereegranskat)abstract
- We have earlier demonstrated sensitive detection of low the volatile nerve agents Tabun, Cyclosarin and VX by using handheld Raman instrumentation in conjunction with surface-enhanced Raman scattering (SERS) attained with gold and silver coated Si nanopillar substrates. In the present proof-of-concept study, the gold substrates chemically are functionalized to realize selectivity towards organophosphorus compounds (OPs) with high sensitivity. A potential capturer and reporter molecule, chemical nerve agent antidote, 4-pyridine amide oxime, is evaluated due to its high Raman cross section, high chemical affinity towards gold, and binding specificity to the target substances Tabun, VX and Cyclosarin via the oxime group. Upon selective and covalent binding, the SERS probe undergoes structural changes which are reflected in the spectral SERS responses, making it suitable for indirect monitoring of nerve agents in aqueous solution. With the probe attached to the hotspots of Au-coated Si nanopillars, the SERS signals distinctly discriminate between specific and non-specific analyte binding of Tabun, Cyclosarin and VX down to sub ppm levels. SERS spectrum of 4-PAO is measured after microliter drop coating of aqueous sample solution onto the functionalized substrates and subsequent water evaporation from surfaces. This binding assay is complemented by letting functionalized substrates being immersed into sample solutions 1 h before measuring. Binding specific SERS response decreases in following order: Tabun > VX > Cyclosarin. Overall, the concept looks promising, as expected the candidate probe 4-PAO introduces selectivity to the nanopillar gold substrates without loss of sensitivity.
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