Can Wu

All Publications

• Design Considerations and Fabrication Protocols of High-Performance Intrinsically Stretchable Transistors and Integrated Circuits. ACS nano Zhong, D., Nishio, Y., Wu, C., Jiang, Y., Wang, W., Yuan, Y., Yao, Y., Tok, J. B., Bao, Z. 2024

  Abstract

  Intrinsically stretchable electronics represent a significant advancement in wearable and implantable technologies, as they offer a unique advantage by maintaining intimate tissue contact while accommodating movements and size changes. This capability makes them exceptionally well-suited for applications in human-machine interfaces, wearables, and implantables, where seamless integration with the human body is essential. To realize this vision, it is important to develop soft integrated circuits for on-body signal processing and computing. Our previous work has focused on developing high-density, intrinsically stretchable transistors capable of delivering high drive current, high-speed performance, and facilitating large-scale integrated circuits. These breakthroughs were achieved through a comprehensive and synergistic approach that encompassed material innovation, meticulous fabrication process design, precise device engineering, and strategic circuit design. Here we provide a comprehensive yet detailed description of these protocols, including design principles, material preparation, fabrication processes, and troubleshooting. These protocols are to empower other researchers to reproduce our developed processes, thus fostering further advancements in stretchable electronics. Specifically, we present in this article an enhanced protocol with explanations, complemented by photographs and instructional videos. This resource aims to bridge the knowledge gap and provide invaluable insights for researchers interested in developing high-performance intrinsically stretchable transistors and integrated circuits. We hope this helps to enable future advancements in the field of intrinsically stretchable electronics.

  View details for DOI 10.1021/acsnano.4c14026

  View details for PubMedID 39563556

• Author Correction: High-speed and large-scale intrinsically stretchable integrated circuits. Nature Zhong, D., Wu, C., Jiang, Y., Yuan, Y., Kim, M. G., Nishio, Y., Shih, C. C., Wang, W., Lai, J. C., Ji, X., Gao, T. Z., Wang, Y. X., Xu, C., Zheng, Y., Yu, Z., Gong, H., Matsuhisa, N., Zhao, C., Lei, Y., Liu, D., Zhang, S., Ochiai, Y., Liu, S., Wei, S., Tok, J. B., Bao, Z. 2024

  View details for DOI 10.1038/s41586-024-07416-x

  View details for PubMedID 38839971

• Strain-Induced Performance Variation in Stretchable Carbon-Nanotube Thin-Film Transistors and the Solution Through a Circular Channel Design IEEE TRANSACTIONS ON ELECTRON DEVICES Wu, C., Zhong, D., Wang, W., Jiang, Y., Nishio, Y., Yuan, Y., Liu, Q., Tok, J., Bao, Z. 2024

  View details for DOI 10.1109/TED.2024.3377188

  View details for Web of Science ID 001197909900001

• High-speed and large-scale intrinsically stretchable integrated circuits. Nature Zhong, D., Wu, C., Jiang, Y., Yuan, Y., Kim, M., Nishio, Y., Shih, C., Wang, W., Lai, J., Ji, X., Gao, T. Z., Wang, Y., Xu, C., Zheng, Y., Yu, Z., Gong, H., Matsuhisa, N., Zhao, C., Lei, Y., Liu, D., Zhang, S., Ochiai, Y., Liu, S., Wei, S., Tok, J. B., Bao, Z. 2024; 627 (8003): 313-320

  Abstract

  Intrinsically stretchable electronics with skin-like mechanical properties have been identified as a promising platform for emerging applications ranging from continuous physiological monitoring to real-time analysis of health conditions, to closed-loop delivery of autonomous medical treatment1-7. However, current technologies could only reach electrical performance at amorphous-silicon level (that is, charge-carrier mobility of about 1cm2V-1s-1), low integration scale (for example, 54 transistors per circuit) and limited functionalities8-11. Here we report high-density, intrinsically stretchable transistors and integrated circuits with high driving ability, high operation speed and large-scale integration. They were enabled by a combination of innovations in materials, fabrication process design, device engineering and circuit design. Our intrinsically stretchable transistors exhibit an average field-effect mobility of more than 20cm2V-1s-1 under 100% strain, a device density of 100,000 transistors per cm2, including interconnects and a high drive current of around 2muAmum-1 at a supply voltage of 5V. Notably, these achieved parameters are on par with state-of-the-art flexible transistors based on metal-oxide, carbon nanotube and polycrystalline silicon materials on plastic substrates12-14. Furthermore, we realize a large-scale integrated circuit with more than 1,000 transistors and a stage-switching frequency greater than 1MHz, for the first time, to our knowledge, in intrinsically stretchable electronics. Moreover, we demonstrate a high-throughput braille recognition system that surpasses human skin sensing ability, enabled by an active-matrix tactile sensor array with a record-high density of 2,500 units per cm2, and a light-emitting diode display with a high refreshing speed of 60Hz and excellent mechanical robustness. The above advancements in device performance have substantially enhanced the abilities of skin-like electronics.

  View details for DOI 10.1038/s41586-024-07096-7

  View details for PubMedID 38480964

• Spiral NeuroString: High-Density Soft Bioelectronic Fibers for Multimodal Sensing and Stimulation. bioRxiv : the preprint server for biology Khatib, M., Zhao, E. T., Wei, S., Abramson, A., Bishop, E. S., Chen, C., Thomas, A., Xu, C., Park, J., Lee, Y., Hamnett, R., Yu, W., Root, S. E., Yuan, L., Chakhtoura, D., Kim, K. K., Zhong, D., Nishio, Y., Zhao, C., Wu, C., Jiang, Y., Zhang, A., Li, J., Wang, W., Salimi-Jazi, F., Rafeeqi, T. A., Hemed, N. M., Tok, J. B., Chen, X., Kaltschmidt, J. A., Dunn, J. C., Bao, Z. 2023

  Abstract

  Bioelectronic fibers hold promise for both research and clinical applications due to their compactness, ease of implantation, and ability to incorporate various functionalities such as sensing and stimulation. However, existing devices suffer from bulkiness, rigidity, limited functionality, and low density of active components. These limitations stem from the difficulty to incorporate many components on one-dimensional (1D) fiber devices due to the incompatibility of conventional microfabrication methods (e.g., photolithography) with curved, thin and long fiber structures. Herein, we introduce a fabrication approach, ‶spiral transformation, to convert two-dimensional (2D) films containing microfabricated devices into 1D soft fibers. This approach allows for the creation of high density multimodal soft bioelectronic fibers, termed Spiral NeuroString (S-NeuroString), while enabling precise control over the longitudinal, angular, and radial positioning and distribution of the functional components. We show the utility of S-NeuroString for motility mapping, serotonin sensing, and tissue stimulation within the dynamic and soft gastrointestinal (GI) system, as well as for single-unit recordings in the brain. The described bioelectronic fibers hold great promises for next-generation multifunctional implantable electronics.

  View details for DOI 10.1101/2023.10.02.560482

  View details for PubMedID 37873341

• Shear-aligned large-area organic semiconductor crystals through extended pi-pi interaction JOURNAL OF MATERIALS CHEMISTRY C Zhang, S., Talnack, F., Jousselin-Oba, T., Bhat, V., Wu, Y., Lei, Y., Tomo, Y., Gong, H., Michalek, L., Zhong, D., Wu, C., Yassar, A., Mannsfeld, S., Risko, C., Frigoli, M., Bao, Z. 2023

  View details for DOI 10.1039/d3tc01311a

  View details for Web of Science ID 001006838400001

• Cost-Effective, Transfer-Free, Flexible Resistive Random Access Memory Using Laser-Scribed Reduced Graphene Oxide Patterning Technology NANO LETTERS Tian, H., Chen, H., Ren, T., Li, C., Xue, Q., Mohammad, M. A., Wu, C., Yang, Y., Wong, H. P. 2014; 14 (6): 3214-3219

  Abstract

  Laser scribing is an attractive reduced graphene oxide (rGO) growth and patterning technology because the process is low-cost, time-efficient, transfer-free, and flexible. Various laser-scribed rGO (LSG) components such as capacitors, gas sensors, and strain sensors have been demonstrated. However, obstacles remain toward practical application of the technology where all the components of a system are fabricated using laser scribing. Memory components, if developed, will substantially broaden the application space of low-cost, flexible electronic systems. For the first time, a low-cost approach to fabricate resistive random access memory (ReRAM) using laser-scribed rGO as the bottom electrode is experimentally demonstrated. The one-step laser scribing technology allows transfer-free rGO synthesis directly on flexible substrates or non-flat substrates. Using this time-efficient laser-scribing technology, the patterning of a memory-array area up to 100 cm(2) can be completed in 25 min. Without requiring the photoresist coating for lithography, the surface of patterned rGO remains as clean as its pristine state. Ag/HfOx/LSG ReRAM using laser-scribing technology is fabricated in this work. Comprehensive electrical characteristics are presented including forming-free behavior, stable switching, reasonable reliability performance and potential for 2-bit storage per memory cell. The results suggest that laser-scribing technology can potentially produce more cost-effective and time-effective rGO-based circuits and systems for practical applications.

  View details for DOI 10.1021/nl5005916

  View details for Web of Science ID 000337337100037