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Lai, L.-L., Huang, P.-H., Stemme, G., Niklaus, F. & Gylfason, K. B. (2024). 3D Printing of Glass Micro-Optics with Subwavelength Features on Optical Fiber Tips. ACS Nano, 18(16), 10788-10797
Open this publication in new window or tab >>3D Printing of Glass Micro-Optics with Subwavelength Features on Optical Fiber Tips
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2024 (English)In: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 18, no 16, p. 10788-10797Article in journal (Refereed) Published
Abstract [en]

Integration of functional materials and structures on the tips of optical fibers has enabled various applications in micro-optics, such as sensing, imaging, and optical trapping. Direct laser writing is a 3D printing technology that holds promise for fabricating advanced micro-optical structures on fiber tips. To date, material selection has been limited to organic polymer-based photoresists because existing methods for 3D direct laser writing of inorganic materials involve high-temperature processing that is not compatible with optical fibers. However, organic polymers do not feature stability and transparency comparable to those of inorganic glasses. Herein, we demonstrate 3D direct laser writing of inorganic glass with a subwavelength resolution on optical fiber tips. We show two distinct printing modes that enable the printing of solid silica glass structures (“Uniform Mode”) and self-organized subwavelength gratings (“Nanograting Mode”), respectively. We illustrate the utility of our approach by printing two functional devices: (1) a refractive index sensor that can measure the indices of binary mixtures of acetone and methanol at near-infrared wavelengths and (2) a compact polarization beam splitter for polarization control and beam steering in an all-in-fiber system. By combining the superior material properties of glass with the plug-and-play nature of optical fibers, this approach enables promising applications in fields such as fiber sensing, optical microelectromechanical systems (MEMS), and quantum photonics.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2024
National Category
Nano Technology
Identifiers
urn:nbn:se:kth:diva-345881 (URN)10.1021/acsnano.3c11030 (DOI)001194459400001 ()2-s2.0-85189353165 (Scopus ID)
Funder
Swedish Foundation for Strategic Research, SSF GMT14-0071Swedish Foundation for Strategic Research, SSF STP19-0014
Note

QC 20240425

Available from: 2024-04-24 Created: 2024-04-24 Last updated: 2024-04-25Bibliographically approved
Enrico, A., Buchmann, S., De Ferrari, F., Lin, Y., Wang, Y., Yue, W., . . . Zeglio, E. (2024). Cleanroom‐Free Direct Laser Micropatterning of Polymers for Organic Electrochemical Transistors in Logic Circuits and Glucose Biosensors. Advanced Science
Open this publication in new window or tab >>Cleanroom‐Free Direct Laser Micropatterning of Polymers for Organic Electrochemical Transistors in Logic Circuits and Glucose Biosensors
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2024 (English)In: Advanced Science, E-ISSN 2198-3844Article in journal (Refereed) Published
Abstract [en]

Organic electrochemical transistors (OECTs) are promising devices for bioelectronics, such as biosensors. However, current cleanroom-based microfabrication of OECTs hinders fast prototyping and widespread adoption of this technology for low-volume, low-cost applications. To address this limitation, a versatile and scalable approach for ultrafast laser microfabrication of OECTs is herein reported, where a femtosecond laser to pattern insulating polymers (such as parylene C or polyimide) is first used, exposing the underlying metal electrodes serving as transistor terminals (source, drain, or gate). After the first patterning step, conducting polymers, such as poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), or semiconducting polymers, are spin-coated on the device surface. Another femtosecond laser patterning step subsequently defines the active polymer area contributing to the OECT performance by disconnecting the channel and gate from the surrounding spin-coated film. The effective OECT width can be defined with high resolution (down to 2 µm) in less than a second of exposure. Micropatterning the OECT channel area significantly improved the transistor switching performance in the case of PEDOT:PSS-based transistors, speeding up the devices by two orders of magnitude. The utility of this OECT manufacturing approach is demonstrated by fabricating complementary logic (inverters) and glucose biosensors, thereby showing its potential to accelerate OECT research.

Place, publisher, year, edition, pages
Wiley, 2024
Keywords
conjugated polymer, direct writing, organic electrochemical transistor, poly(3, 4-ethylenedioxythiophene) polystyrene sulfonate, ultrashort pulsed lasers
National Category
Organic Chemistry Other Electrical Engineering, Electronic Engineering, Information Engineering Other Materials Engineering
Identifiers
urn:nbn:se:kth:diva-342521 (URN)10.1002/advs.202307042 (DOI)001142422700001 ()2-s2.0-85182492139 (Scopus ID)
Funder
Swedish Research Council, 2018‐03483Swedish Research Council, 2022‐04060Swedish Research Council, 2022‐02855Knut and Alice Wallenberg Foundation, 2015.0178Knut and Alice Wallenberg Foundation, 2020.0206Knut and Alice Wallenberg Foundation, 2021.0312Swedish Research Council, 2022-00374
Note

QC 20240123

Available from: 2024-01-23 Created: 2024-01-23 Last updated: 2024-02-06Bibliographically approved
Tian, X., Iordanidis, T. N., Stemme, G. & Roxhed, N. (2024). Low-Temperature Integration of Bulk PZT-5H for Enhancing the Performance of MEMS-Based Piezoelectric Ultrasonic Energy Harvesters. In: IEEE 37th International Conference on Micro Electro Mechanical Systems, MEMS 2024: . Paper presented at 37th IEEE International Conference on Micro Electro Mechanical Systems, MEMS 2024, Austin, United States of America, Jan 21 2024 - Jan 25 2024 (pp. 749-752). Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>Low-Temperature Integration of Bulk PZT-5H for Enhancing the Performance of MEMS-Based Piezoelectric Ultrasonic Energy Harvesters
2024 (English)In: IEEE 37th International Conference on Micro Electro Mechanical Systems, MEMS 2024, Institute of Electrical and Electronics Engineers (IEEE) , 2024, p. 749-752Conference paper, Published paper (Refereed)
Abstract [en]

We demonstrate a low-temperature fabricated MEMS-based piezoelectric ultrasonic energy harvester with enhanced device performance. Compared to state-of-the-art, our work uses a low-temperature bonding method, which ensures the integrated piezoelectric material undergoes prominently lower temperatures (≤ 85 °C) throughout the whole fabrication process. Due to this, bulk PZT-5H, a material with superior piezoelectric properties, could be used in this type of application for the first time. The method guarantees the device fabrication temperature well below the PZT-5H Curie temperature (225 °C) and preserves its piezoelectricity to the greatest extent. As a result, devices fabricated using the proposed method achieve higher performance than the devices prepared by the MEMS fabrication method using BCB bonding. The root-mean-square voltage and the average power outputs at the frequency (170 kHz) where maximum voltage and power outputs were observed were improved by 38 % and 92 %, respectively.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2024
Keywords
Piezoelectric energy harvester, power transfer, ultrasonic transducer
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:kth:diva-344356 (URN)10.1109/MEMS58180.2024.10439532 (DOI)001174201100193 ()2-s2.0-85186701633 (Scopus ID)
Conference
37th IEEE International Conference on Micro Electro Mechanical Systems, MEMS 2024, Austin, United States of America, Jan 21 2024 - Jan 25 2024
Note

Part of ISBN 9798350357929

QC 20240315

Available from: 2024-03-13 Created: 2024-03-13 Last updated: 2024-04-26Bibliographically approved
Pagliano, S., Schröder, S., Stemme, G. & Niklaus, F. (2023). 3D Printing by Two-Photon Polymerization of Polyimide Objects and Demonstration of a 3D-printed Micro-Hotplate. Advanced Materials Technologies, 8(19), Article ID 2300229.
Open this publication in new window or tab >>3D Printing by Two-Photon Polymerization of Polyimide Objects and Demonstration of a 3D-printed Micro-Hotplate
2023 (English)In: Advanced Materials Technologies, E-ISSN 2365-709X, Vol. 8, no 19, article id 2300229Article in journal (Refereed) Published
Abstract [en]

Polyimides are polymeric materials with outstanding thermal, chemical, and mechanical properties. For this reason, they find applications in several engineering sectors, including aerospace, microsystems, and biomedical applications. For realizing 3D structures made of polyimides, 3D printing is an attractive technique because it overcomes the limitations of polyimide processing using conventional manufacturing techniques such as molding and subtractive manufacturing. However, current polyimide 3D printing approaches are limited to realizing objects with the smallest dimensions of the order of a few hundred micrometers. 3D printing of polyimide objects featuring sub-micrometer resolution using two-photon polymerization by direct laser writing is demonstrated here. A negative photosensitive polyimide is applied that is widely used in microsystems applications. To demonstrate the utility of this polyimide 3D printing approach and the compatibility of the 3D objects with operation at elevated temperatures, a micro-hotplate is 3D printed and characterized at operating temperatures of above 300 °C.

Place, publisher, year, edition, pages
Wiley, 2023
Keywords
flexible photodetectors, full-spectrum detections, near-infrared imaging, near-infrared organic photodetectors, ultranarrow bandgap non-fullerene acceptors
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-338507 (URN)10.1002/admt.202300229 (DOI)001049272200001 ()2-s2.0-85167835586 (Scopus ID)
Note

QC 20231115

Available from: 2023-11-15 Created: 2023-11-15 Last updated: 2023-11-15Bibliographically approved
Pagliano, S., Marschner, D. E., Maillard, D., Ehrmann, N., Stemme, G., Braun, S., . . . Niklaus, F. (2023). A 3D-Printed Functional Mems Accelerometer. In: 2023 IEEE 36TH INTERNATIONAL CONFERENCE ON MICRO ELECTRO MECHANICAL SYSTEMS, MEMS: . Paper presented at 36th IEEE International Conference on Micro Electro Mechanical Systems (MEMS), JAN 15-19, 2023, Munich, GERMANY (pp. 594-597). Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>A 3D-Printed Functional Mems Accelerometer
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2023 (English)In: 2023 IEEE 36TH INTERNATIONAL CONFERENCE ON MICRO ELECTRO MECHANICAL SYSTEMS, MEMS, Institute of Electrical and Electronics Engineers (IEEE) , 2023, p. 594-597Conference paper, Published paper (Refereed)
Abstract [en]

3D printing of MEMS devices could enable the cost-efficient production of custom-designed and complex 3D MEMS for prototyping and for low-volume applications. In this work, we present the first micro 3D-printed functional MEMS accelerometers using two-photon polymerization combined with the evaporation of metal strain gauge transducers. We measured the resonance frequency, the responsivity, and the signal stability over a period of 10 h of the 3D-printed accelerometer.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2023
Series
Proceedings IEEE Micro Electro Mechanical Systems, ISSN 1084-6999
Keywords
3D printing, two-photon polymerization, shadow masking, strain gauge transducer, Laser Doppler Vibrometer, custom MEMS, low-volume manufacturing
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-328424 (URN)10.1109/MEMS49605.2023.10052385 (DOI)000975359200156 ()2-s2.0-85149826299 (Scopus ID)
Conference
36th IEEE International Conference on Micro Electro Mechanical Systems (MEMS), JAN 15-19, 2023, Munich, GERMANY
Note

QC 20230613

Available from: 2023-06-13 Created: 2023-06-13 Last updated: 2023-06-13Bibliographically approved
Hauser, J., Dale, M., Beck, O., Schwenk, J. M., Stemme, G., Fredolini, C. & Roxhed, N. (2023). Microfluidic Device for Patient-Centric Multiplexed Assays with Readout in Centralized Laboratories. Analytical Chemistry, 95(2), 1350-1358
Open this publication in new window or tab >>Microfluidic Device for Patient-Centric Multiplexed Assays with Readout in Centralized Laboratories
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2023 (English)In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 95, no 2, p. 1350-1358Article in journal (Refereed) Published
Abstract [en]

Patient-centric sampling strategies, where the patient performs self-sampling and ships the sample to a centralized laboratory for readout, are on the verge of widespread adaptation. However, the key to a successful patient-centric workflow is user-friendliness, with few noncritical user interactions, and simple, ideally biohazard-free shipment. Here, we present a capillary-driven microfluidic device designed to perform the critical biomarker capturing step of a multiplexed immunoassay at the time of sample collection. On-chip sample drying enables biohazard-free shipment and allows us to make use of advanced analytics of specialized laboratories that offer the needed analytical sensitivity, reliability, and affordability. Using C-Reactive Protein, MCP1, S100B, IGFBP1, and IL6 as model blood biomarkers, we demonstrate the multiplexing capability and applicability of the device to a patient-centric workflow. The presented quantification of a biomarker panel opens up new possibilities for e-doctor and e-health applications.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2023
National Category
Analytical Chemistry
Identifiers
urn:nbn:se:kth:diva-330103 (URN)10.1021/acs.analchem.2c04318 (DOI)000905022600001 ()36548393 (PubMedID)2-s2.0-85144835090 (Scopus ID)
Note

QC 20230626

Available from: 2023-06-26 Created: 2023-06-26 Last updated: 2023-06-26Bibliographically approved
Ribet, F., Bendes, A., Fredolini, C., Dobielewski, M., Böttcher, M., Beck, O., . . . Roxhed, N. (2023). Microneedle Patch for Painless Intradermal Collection of Interstitial Fluid Enabling Multianalyte Measurement of Small Molecules, SARS‐CoV‐2 Antibodies, and Protein Profiling. Advanced Healthcare Materials, 12(13)
Open this publication in new window or tab >>Microneedle Patch for Painless Intradermal Collection of Interstitial Fluid Enabling Multianalyte Measurement of Small Molecules, SARS‐CoV‐2 Antibodies, and Protein Profiling
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2023 (English)In: Advanced Healthcare Materials, ISSN 2192-2640, E-ISSN 2192-2659, Vol. 12, no 13Article in journal (Refereed) Published
Abstract [en]

Blood sampling is a common practice to monitor health, but it entails a series of drawbacks for patients including pain and discomfort. Thus, there is a demand for more convenient ways to obtain samples. Modern analytical techniques enable monitoring of multiple bioanalytes in smaller samples, opening possibilities for new matrices, and microsampling technologies to be adopted. Interstitial fluid (ISF) is an attractive alternative matrix that shows good correlation with plasma concentration dynamics for several analytes and can be sampled in a minimally invasive and painless manner from the skin at the point-of-care. However, there is currently a lack of sampling devices compatible with clinical translation. Here, to tackle state-of-the-art limitations, a cost-effective and compact single-microneedle-based device designed to painlessly collect precisely 1.1 µL of dermal ISF within minutes is presented. The fluid is volume-metered, dried, and stably stored into analytical-grade paper within the microfluidic device. The obtained sample can be mailed to a laboratory, quantitatively analyzed, and provide molecular insights comparable to blood testing. In a human study, the possibility to monitor various classes of molecular analytes is demonstrated in ISF microsamples, including caffeine, hundreds of proteins, and SARS-CoV-2 antibodies, some being detected in ISF for the first time.

Place, publisher, year, edition, pages
Wiley, 2023
Keywords
COVID-19, health monitoring medical devices, interstitial fluids, microneedles, painless microsampling
National Category
Medical Engineering
Research subject
Applied Medical Technology; Technology and Health; Medical Technology
Identifiers
urn:nbn:se:kth:diva-328889 (URN)10.1002/adhm.202202564 (DOI)000935875000001 ()36748807 (PubMedID)2-s2.0-85148644132 (Scopus ID)
Funder
Swedish Foundation for Strategic ResearchEU, Horizon 2020, 101017899Olle Engkvists stiftelse, 2016/178
Note

QC 20230614

Available from: 2023-06-13 Created: 2023-06-13 Last updated: 2023-06-14Bibliographically approved
Lai, L.-L., Huang, P.-H., Stemme, G., Niklaus, F. & Gylfason, K. (2023). Picoliter-volume refractive index sensor 3D-printed in silica glass on an optical fiber tip. In: 2023 Conference on Lasers and Electro-Optics, CLEO 2023: . Paper presented at 2023 Conference on Lasers and Electro-Optics, CLEO 2023, San Jose, United States of America, May 7 2023 - May 12 2023. Institute of Electrical and Electronics Engineers Inc., Article ID AM4K.1.
Open this publication in new window or tab >>Picoliter-volume refractive index sensor 3D-printed in silica glass on an optical fiber tip
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2023 (English)In: 2023 Conference on Lasers and Electro-Optics, CLEO 2023, Institute of Electrical and Electronics Engineers Inc. , 2023, article id AM4K.1Conference paper, Published paper (Refereed)
Abstract [en]

We demonstrate a refractive index sensor additively 3D-printed in silica glass on an optical fiber tip. The sensor shows a sensitivity of 900 nm/RIU and measures a liquid volume as small as 0.6 pl.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2023
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:kth:diva-339979 (URN)2-s2.0-85176336459 (Scopus ID)
Conference
2023 Conference on Lasers and Electro-Optics, CLEO 2023, San Jose, United States of America, May 7 2023 - May 12 2023
Note

Part of ISBN 9781957171258

QC 20231124

Available from: 2023-11-24 Created: 2023-11-24 Last updated: 2023-11-24Bibliographically approved
Buchmann, S., Enrico, A., Holzreuter, M. A., Reid, M. S., Zeglio, E., Niklaus, F., . . . Herland, A. (2023). Probabilistic cell seeding and non-autofluorescent 3D-printed structures as scalable approach for multi-level co-culture modeling. Materials Today Bio, 21, 100706-100706, Article ID 100706.
Open this publication in new window or tab >>Probabilistic cell seeding and non-autofluorescent 3D-printed structures as scalable approach for multi-level co-culture modeling
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2023 (English)In: Materials Today Bio, ISSN 2590-0064, Vol. 21, p. 100706-100706, article id 100706Article in journal (Refereed) Published
Abstract [en]

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.

Place, publisher, year, edition, pages
Elsevier BV, 2023
Keywords
Two-photon polymerization Neurons Astrocytes Calcium imaging Co-culture models IP-Visio
National Category
Nano Technology Bio Materials Cell Biology
Identifiers
urn:nbn:se:kth:diva-331732 (URN)10.1016/j.mtbio.2023.100706 (DOI)001030630300001 ()37435551 (PubMedID)2-s2.0-85166735644 (Scopus ID)
Note

Correction in Materials Today Bio, vol. 23. DOI:10.1016/j.mtbio.2023.100892

QC 20231221

Available from: 2023-07-14 Created: 2023-07-14 Last updated: 2024-02-06Bibliographically approved
Last, T., Pagliano, S., Iordanidis, T. N., Niklaus, F., Stemme, G. & Roxhed, N. (2023). Scaling toward Diminutive MEMS: Dust-Sized Spray Chips for Aerosolized Drug Delivery to the Lung. Advanced Materials Technologies, 8(7), Article ID 2201260.
Open this publication in new window or tab >>Scaling toward Diminutive MEMS: Dust-Sized Spray Chips for Aerosolized Drug Delivery to the Lung
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2023 (English)In: Advanced Materials Technologies, E-ISSN 2365-709X, Vol. 8, no 7, article id 2201260Article in journal (Refereed) Published
Abstract [en]

The functional area of silicon-based microelectromechanical systems (MEMS) devices often occupies only a fraction of the actual silicon area of the chip. As the chip cost directly scales with the total chip area, there is an incentive to reduce the chip to the smallest possible size. However, handling such diminutive devices poses challenges that industry-standard packaging cannot solve. Here, the world's smallest spray nozzle chip for drug delivery to the lung is manufactured and packaged and how magnetic assembly combined with microfluidic glue fixation can overcome this barrier for diminutive MEMS devices is demonstrated. The spray nozzle chips have a circular footprint with a diameter of 280 µm and feature a nickel coating on their conical sidewall, allowing magnetic manipulation. The chips are assembled and sealed into plastic substrates using a three-step gluing process guided by capillary action and activated by heat. Assembly speeds of up to 147 chips per minute are demonstrated and fabrication to packaging and functional operation of this device is shown for the target application.

Place, publisher, year, edition, pages
Wiley, 2023
Keywords
aerosol drug delivery, magnetic assembly, microfluidics, packaging, portable inhaler, silicon on insulator
National Category
Other Medical Engineering
Identifiers
urn:nbn:se:kth:diva-331086 (URN)10.1002/admt.202201260 (DOI)000946788600001 ()2-s2.0-85150624729 (Scopus ID)
Note

QC 20230706

Available from: 2023-07-06 Created: 2023-07-06 Last updated: 2023-07-06Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0001-9552-4234

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