| 1. |
- Enrico, Alessandro
(författare)
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Bright Lights: Innovative Micro- and Nano-Patterning for Sensing and Tissue Engineering
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Light is the primary source of energy on our planet and has been a significant driver in the evolution of human society and technology. Light finds applications in two-dimensional (2D) photolithography and three-dimensional (3D) printing, where a pattern is transferred to a material of interest by ultraviolet (UV) light exposure, and in laser scribing and cutting, where high power lasers are used to pattern the surface of objects or cut through the bulk of the material of interest. However, conventional light-based processing has three main constraints: a) the wavelength of visible light limits resolution, b) only materials that absorb the wavelength in use can be efficiently processed, and c) intense laser light burns its target, degrading the material surrounding the exposed areas and further limiting material compatibility. Overcoming these limitations is the core of this thesis.The first part of this thesis describes three different patterning methods enabled by intelligent design and non-linear light-matter interaction. The first work reports the use of light at 365 nm to generate sub-20 nm wide nanowires (NWs) exploiting crack lithography, exceeding the possible resolution given by diffraction limit by 10-fold. The second work describes how the non-linear interaction of femtosecond laser pulses with otherwise transparent glass enables nanostructuring of borosilicate coverslips. Positively charging the nanostructured glass surfaces grants a “attract and destroy” bactericidal functionality and maintains the transparency of the substrate, creating a microscopy compatible platform to study bacteria-surface interactions and providing strategies to fight antibiotic-resistant bacteria. The third and fourth works show how femtosecond lasers can directly pattern carbon nanotube films and 2D materials (graphene, molybdenum disulfide, and platinum diselenide) without damaging the substrate or the material surrounding the exposed area. Non-linear interaction with high-energy laser pulses allows sub-300 nm resolution, circumventing the limit given by light diffraction in the linear regime. The combination of high resolution, femtosecond exposure, and ultrafast scanning speed provides a valid alternative to resist-based photolithography while eliminating the related contamination issues for these sensitive materials.The second part of this thesis describes two different 3D micromachining approaches enabled by high-intensity laser light. The fifth work presents a collagen patterning method based on laser-induced cavitation, called cavitation molding. This method represents a new biomanufacturing mode that is neither additive nor subtractive. In this study, cavitation molding enables the generation of a micro vascularized cancer-on-chip model, consisting of an in-vivo-like spheroidal mass of cancer cells surrounded by artificial blood vessels. In the sixth and final work, we used two-photon polymerization to generate 3D platforms in a biocompatible resin. This platform enables the study of the physiology of neurons and their interaction with astrocyte cells. The low autofluorescence of the printed resins allows optical readout of the neuronal activity by calcium imaging.
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| 2. |
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| 3. |
- Bleiker, Simon J., et al.
(författare)
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Device with a waveguide supported on a substrate and method for its fabrication
- 2020
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Patent (populärvet., debatt m.m.)abstract
- ABSTRACT A device (1) and a method for fabricating such a device is described. The device (1) comprises a device layer (4), a substrate (2) defining a substrate plane (3). A device layer plane (5) is defined on the side of the device layer (4) facing the substrate (2). The device also comprises a waveguide (7) for guiding an electromagnetic wave. The waveguide (7) is supported on the substrate (2) via a support structure (6) extending from the substrate (2) to the device layer (4). The ratio of the largest distance (D1), perpendicular to the substrate plane (3), between a free surface of the waveguide (7) facing the substrate and any solid material to the height (h) of the waveguide (7) is more than 6, i.e. D1/h \textgreater 6. The ratio of the distance (D2), perpendicular to the substrate plane (3), between the device layer plane (5) and the substrate plane (3) to the height (h) of the waveguide (7) is more than 6, i.e. D2/h \textgreater 6.
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| 4. |
- Bogaerts, Wim, et al.
(författare)
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MORPHIC : Programmable Photonic Circuits enabled by Silicon Photonic MEMS
- 2020
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Ingår i: Proceedings Volume 11285 SPIE OPTO - 1-6 February 2020 Silicon Photonics XV. - : SPIE-Intl Soc Optical Eng.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In the European project MORPHIC we develop a platform for programmable silicon photonic circuits enabled by waveguide-integrated micro-electro-mechanical systems (MEMS). MEMS can add compact, and low-power phase shifters and couplers to an established silicon photonics platform with high-speed modulators and detectors. This MEMS technology is used for a new class of programmable photonic circuits, that can be reconfigured using electronics and software, consisting of large interconnected meshes of phase shifters and couplers. MORPHIC is also developing the packaging and driver electronics interfacing schemes for such large circuits, creating a supply chain for rapid prototyping new photonic chip concepts. These will be demonstrated in different applications, such as switching, beamforming and microwave photonics.
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| 5. |
- Bogaerts, Wim, et al.
(författare)
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Programmable Photonic Circuits powered by Silicon Photonic MEMS Technology
- 2022
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Ingår i: Photonic Networks and Devices, Networks 2022. - : Optica Publishing Group (formerly OSA).
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Konferensbidrag (refereegranskat)abstract
- Programmable photonic chips allow flexible reconfiguration of on-chip optical connections, controlled through electronics and software. We will present the recent progress of such complex photonic circuits powered by silicon photonic MEMS actuators.
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| 6. |
- Bogaerts, W., et al.
(författare)
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Programmable photonic circuits using silicon photonic MEMS
- 2021
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Ingår i: Optics InfoBase Conference Papers. - : The Optical Society.
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Konferensbidrag (refereegranskat)abstract
- We present a silicon photonics technology extended with low-power MEMS scalable to large circuits. This enables us to make photonic waveguide meshes that can be reconfigured using electronics and software.
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| 7. |
- Bogaerts, Wim, et al.
(författare)
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Programmable silicon photonic circuits powered by MEMS
- 2022
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE-Intl Soc Optical Eng.
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Konferensbidrag (refereegranskat)abstract
- We present our work to extend silicon photonics with MEMS actuators to enable low-power, large scale programmable photonic circuits. For this, we start from the existing iSiPP50G silicon photonics platform of IMEC, where we add free-standing movable waveguides using a few post-processing steps. This allows us to implement phase shifters and tunable couplers using electrostatically actuated MEMS, while at the same time maintaining all the original functionality of the silicon photonics platform. The MEMS devices are protected using a wafer-level sealing approach and interfaced with custom multi-channel driver and readout electronics.
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| 8. |
- Bogaerts, Wim, et al.
(författare)
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Scaling programmable silicon photonics circuits
- 2023
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Ingår i: Silicon Photonics XVIII. - : SPIE-Intl Soc Optical Eng.
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Konferensbidrag (refereegranskat)abstract
- We give an overview the progress of our work in silicon photonic programmable circuits, covering the techn stack from the photonic chip over the driver electronics, packaging technologies all the way to the sof layers. On the photonic side, we show our recent results in large-scale silicon photonic circuits with diff tuning technologies, including heaters, MEMS and liquid crystals, and their respective electronic driving sch We look into the scaling potential of these different technologies as the number of tunable elements in a ci increases. Finally, we elaborate on the software routines for routing and filter synthesis to enable the pho programmer.
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| 10. |
- Buchmann, Sebastian, et al.
(författare)
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Probabilistic cell seeding and non-autofluorescent 3D-printed structures as scalable approach for multi-level co-culture modeling
- 2023
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Ingår i: Materials Today Bio. - : Elsevier BV. - 2590-0064. ; 21, s. 100706-100706
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Tidskriftsartikel (refereegranskat)abstract
- To model complex biological tissue in vitro, a specific layout for the position and numbers of each cell type isnecessary. Establishing such a layout requires manual cell placement in three dimensions (3D) with micrometricprecision, which is complicated and time-consuming. Moreover, 3D printed materials used in compartmentalizedmicrofluidic models are opaque or autofluorescent, hindering parallel optical readout and forcing serial charac-terization methods, such as patch-clamp probing. To address these limitations, we introduce a multi-level co-culture model realized using a parallel cell seeding strategy of human neurons and astrocytes on 3D structuresprinted with a commercially available non-autofluorescent resin at micrometer resolution. Using a two-stepstrategy based on probabilistic cell seeding, we demonstrate a human neuronal monoculture that forms net-works on the 3D printed structure and can establish cell-projection contacts with an astrocytic-neuronal co-cultureseeded on the glass substrate. The transparent and non-autofluorescent printed platform allows fluorescence-based immunocytochemistry and calcium imaging. This approach provides facile multi-level compartmentaliza-tion of different cell types and routes for pre-designed cell projection contacts, instrumental in studying complextissue, such as the human brain.
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