Caofeng Pan

Flexible Thin Film Electronics

Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, China, 100085

Email: cfpan@binn.cas.cn

Biography

Professor Caofeng Pan is a professor and a group leader at Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences (BINN, CAS) and school of Nanoscience and nanotechnology, University of Chinese Academy of Sciences and he is a winner of The National Science Fund for Distinguished Young Scholars. He received his B.S. degree (2005) and his Ph.D. (2010) in Materials Science and Engineering from Tsinghua University, China. He joined the Georgia Institute of Technology as a postdoctoral fellow, then he joined BINN, CAS in 2013. His main research interests focus on the fields of piezotronics for fabricating smart electronic and optoelectronic devices for tactile sensing. Prof. Pan is the Associate Editor of Science Bulletin, and Nanotechnology, and serves on editorial boards of 5 other journals. He has published more than 230 research papers in journals including, Nature Photonics, Nature Communications, Advanced Materials, Chemical Reviews etc, He holds 3 US patents and over 40 Chinese patents. He has won first prize of Natural Science in Henan Province.

Abstract for Presentation

Mapping strain/pressure with ZnO nanowire arrays by piezotronic and piezo-phototronic effect

Emulation of human senses via electronic means has long been a grand challenge in research of artificial intelligence as well as prosthetics, and is of pivotal importance for developing intelligently accessible and natural interfaces between human/environment and machine.

In this talk, we present a novel design of nanowire LED arrays, which can be used to directly record the strain distribution by piezo-phototronic effect with a resolution as high as 2.7 μm, which is published in Nat. Photonics. Such sensors are capable of recording spatial profiles of pressure distribution, and the tactile pixel area density of our device array is 6250000/cm2, which is much higher than the number of mechanoreceptors embedded in the human fingertip skins (~ 240/cm2).

When the device is under pressure, the images unambiguously show that the change in LED intensity occurred apparently at the pixels that were being compressed by the molded pattern, while those were off the molded characters showed almost no change in LED intensity. Instead of using the cross-bar electrodes for sequential data output, the pressure image is read out in parallel for all of the pixels at a response and recovery time-resolution of 90 ms. Furthermore, our recent studies achieve such piezo-phototronic effect induced strain mapping in a flexible n-ZnO NWs/p-polymer LEDs array system. This may be a major step toward digital imaging of mechanical signals by optical means, with potential applications in touch pad technology, personalized signatures, bio-imaging and optical MEMS.

This research not only introduce a novel approach to fabricate Si-based or polymer-based flexible light-emitting components with high performances, but also may be a great step toward digital imaging of mechanical signals using optical means, having potential applications in artificial skin, touch pad technology, personalized signatures, bio-imaging and optical MEMS, and even and smart skin.

References

[1] Pan, C. F. et al. High-resolution electroluminescent imaging of pressure distribution using a piezoelectric nanowire LED array. Nat. Photon. 7, 752-758

[2] Bao, R. R. et al. Flexible and Controllable Piezo-Phototronic Pressure Mapping Sensor Matrix by ZnO NW/p-Polymer LED Array. Adv. Funct. Mater. 25, 2884-2891

[3] Li, X. Y. et al. Enhancing Light Emission of ZnO-Nanofilm/Si-Micropillar Heterostructure Arrays by Piezo-Phototronic Effect. Adv. Mater. 27, 4447-4453