All Publications

  • 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


    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


    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

  • Tunable 1D and 2D Polyacrylonitrile Nanosheet Superstructures. ACS nano Gong, H., Patino, D. U., Ilavsky, J., Kuzmenko, I., Peña-Alcántara, A. E., Zhu, C., Coffey, A. H., Michalek, L., Elabd, A., Gao, X., Chen, S., Xu, C., Yan, H., Jiang, Y., Wang, W., Peng, Y., Zeng, Y., Lyu, H., Moon, H., Bao, Z. 2023


    Carbon superstructures are widely applied in energy and environment-related areas. Among them, the flower-like polyacrylonitrile (PAN)-derived carbon materials have shown great promise due to their high surface area, large pore volume, and improved mass transport. In this work, we report a versatile and straightforward method for synthesizing one-dimensional (1D) nanostructured fibers and two-dimensional (2D) nanostructured thin films based on flower-like PAN chemistry by taking advantage of the nucleation and growth behavior of PAN. The resulting nanofibers and thin films exhibited distinct morphologies with intersecting PAN nanosheets, which formed through rapid nucleation on existing PAN. We further constructed a variety of hierarchical PAN superstructures based on different templates, solvents, and concentrations. These PAN nanosheet superstructures can be readily converted to carbon superstructures. As a demonstration, the nanostructured thin film exhibited a contact angle of ∼180° after surface modification with fluoroalkyl monolayers, which is attributed to high surface roughness enabled by the nanosheet assemblies. This study offers a strategy for the synthesis of nanostructured carbon materials for various applications.

    View details for DOI 10.1021/acsnano.3c05792

    View details for PubMedID 37668312

  • Neuromorphic sensorimotor loop embodied by monolithically integrated, low-voltage, soft e-skin. Science (New York, N.Y.) Wang, W., Jiang, Y., Zhong, D., Zhang, Z., Choudhury, S., Lai, J. C., Gong, H., Niu, S., Yan, X., Zheng, Y., Shih, C. C., Ning, R., Lin, Q., Li, D., Kim, Y. H., Kim, J., Wang, Y. X., Zhao, C., Xu, C., Ji, X., Nishio, Y., Lyu, H., Tok, J. B., Bao, Z. 2023; 380 (6646): 735-742


    Artificial skin that simultaneously mimics sensory feedback and mechanical properties of natural skin holds substantial promise for next-generation robotic and medical devices. However, achieving such a biomimetic system that can seamlessly integrate with the human body remains a challenge. Through rational design and engineering of material properties, device structures, and system architectures, we realized a monolithic soft prosthetic electronic skin (e-skin). It is capable of multimodal perception, neuromorphic pulse-train signal generation, and closed-loop actuation. With a trilayer, high-permittivity elastomeric dielectric, we achieved a low subthreshold swing comparable to that of polycrystalline silicon transistors, a low operation voltage, low power consumption, and medium-scale circuit integration complexity for stretchable organic devices. Our e-skin mimics the biological sensorimotor loop, whereby a solid-state synaptic transistor elicits stronger actuation when a stimulus of increasing pressure is applied.

    View details for DOI 10.1126/science.ade0086

    View details for PubMedID 37200416

  • Octopus-inspired deception and signaling systems from an exceptionally-stable acene variant Nature Communications Pratakshya*, P., Xu*, C., Dibble*, D., et al 2023; 14 (1): 8528
  • Fast-Charging of Hybrid Lithium-Ion/Lithium-Metal Anodes by Nanostructured Hard Carbon Host ACS ENERGY LETTERS Gong, H., Chen, Y., Chen, S., Xu, C., Yang, Y., Ye, Y., Huang, Z., Ning, R., Cui, Y., Bao, Z. 2022; 7 (12): 4417-4426
  • High-brightness all-polymer stretchable LED with charge-trapping dilution. Nature Zhang, Z., Wang, W., Jiang, Y., Wang, Y., Wu, Y., Lai, J., Niu, S., Xu, C., Shih, C., Wang, C., Yan, H., Galuska, L., Prine, N., Wu, H., Zhong, D., Chen, G., Matsuhisa, N., Zheng, Y., Yu, Z., Wang, Y., Dauskardt, R., Gu, X., Tok, J. B., Bao, Z. 2022; 603 (7902): 624-630


    Next-generation light-emitting displays on skin should be soft, stretchable and bright1-7. Previously reported stretchable light-emitting devices were mostly basedon inorganic nanomaterials, such as light-emitting capacitors, quantum dots or perovskites6-11. They either require high operating voltage or have limited stretchability and brightness, resolution or robustness under strain. On the other hand, intrinsically stretchable polymer materials hold the promise of good strain tolerance12,13. However, realizing high brightness remains a grand challenge for intrinsically stretchable light-emitting diodes. Here we report a material design strategy and fabrication processes to achieve stretchable all-polymer-based light-emitting diodes with high brightness (about 7,450candela per square metre), current efficiency (about 5.3candela per ampere) and stretchability (about 100per cent strain). We fabricate stretchable all-polymer light-emitting diodes coloured red, green and blue, achieving both on-skin wireless powering and real-time displaying of pulse signals. This work signifies a considerable advancement towards high-performance stretchable displays.

    View details for DOI 10.1038/s41586-022-04400-1

    View details for PubMedID 35322250

  • Long-Range Proton Transport in Films from a Reflectin-Derived Polypeptide ACS Applied Materials & Interfaces Xu, C., et al 2021; 13 (18): 20938-20946

    View details for DOI 10.1021/acsami.0c18929

  • Stretchable Cephalopod‐Inspired Multimodal Camouflage Systems Advanced Materials Xu, C., Colorado Escobar, M., Gorodetsky, A. A. 2020; 32 (16)

    View details for DOI 10.1002/adma.201905717

  • Adaptive infrared-reflecting systems inspired by cephalopods Science Xu, C., Stiubianu, G. T., Gorodetsky, A. A. 2018; 359 (6383): 1495-1500

    View details for DOI 10.1126/science.aar5191