Shuhan Liu

All Publications

• Design Guidelines for Oxide Semiconductor Gain Cell Memory on a Logic Platform IEEE TRANSACTIONS ON ELECTRON DEVICES Liu, S., Jana, K., Toprasertpong, K., Chen, J., Liang, Z., Jiang, Q., Wahid, S., Qin, S., Chen, W., Pop, E., Wong, H. 2024

  View details for DOI 10.1109/TED.2024.3372938

  View details for Web of Science ID 001205833400001

• 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

• Hybrid 2T nMOS/pMOS Gain Cell Memory With Indium-Tin-Oxide and Carbon Nanotube MOSFETs for Counteracting Capacitive Coupling IEEE ELECTRON DEVICE LETTERS Liu, S., Li, S., Lin, Q., Jana, K., Mitra, S., Wong, H., Toprasertpong, K. 2024; 45 (2): 188-191

  View details for DOI 10.1109/LED.2023.3344370

  View details for Web of Science ID 001173363300012

• Monolithic optical microlithography of high-density elastic circuits. Science (New York, N.Y.) Zheng, Y. Q., Liu, Y., Zhong, D., Nikzad, S., Liu, S., Yu, Z., Liu, D., Wu, H. C., Zhu, C., Li, J., Tran, H., Tok, J. B., Bao, Z. 2021; 373 (6550): 88-94

  Abstract

  Polymeric electronic materials have enabled soft and stretchable electronics. However, the lack of a universal micro/nanofabrication method for skin-like and elastic circuits results in low device density and limited parallel signal recording and processing ability relative to silicon-based devices. We present a monolithic optical microlithographic process that directly micropatterns a set of elastic electronic materials by sequential ultraviolet light-triggered solubility modulation. We fabricated transistors with channel lengths of 2 micrometers at a density of 42,000 transistors per square centimeter. We fabricated elastic circuits including an XOR gate and a half adder, both of which are essential components for an arithmetic logic unit. Our process offers a route to realize wafer-level fabrication of complex, high-density, and multilayered elastic circuits with performance rivaling that of their rigid counterparts.

  View details for DOI 10.1126/science.abh3551

  View details for PubMedID 34210882