Qibing Pei is professor of materials science and engineering specializing in electroactive polymers. He worked successively as a senior chemist at UNIAX Corporation, Santa Barbara, CA, which was later merged into DuPont Display, a senior chemist at Imation Corporation, Santa Paul, MN, and a senior research engineer at SRI International, Menlo Park, CA. He has developed a number of electronic and electroactive polymers for applications in electro-optic and electro-mechanical devices, including light emitting diodes, polymer light emitting electrochemical cells, electroactive polymer artificial muscles, and biologically-inspired robots. His research interests cover a wide range of soft materials and span from material synthesis, processing, to design of functional devices. He applies polymer synthesis, solution-based processing and nanofabrication in the discovery of new functional polymers and composites. He has published about 120 papers in refereed journals with 8000 SCI citations and an H-factor of 41. He is inventor or co-inventor of 39 US patents.

Our Soft Materials Research Laboratory studies electroactive polymers and nanostructured hybrid materials. The research focuses on molecular synthesis and nanofabrication for the development of new polymers and nanostructures with desired electronic, photonic, and/or mechanical properties. The applications of these materials are many folds, including flexible electronics, artificial muscles, photovoltaics, wind energy generation, radiation detection and protection, and biologically-inspired systems to name a few. Current activities include: Artificial Muscles: These are based on dielectric elastomers exhibiting electrically-induced strains as high as 300%. The polymer transducers have such advantages as high energy and power densities, quietness, mechanical compliancy (for shock resistance and impedance matching), high efficiency, lightweight, and low cost. To improve the device performance and reliability, interpenetrating polymer networks are being studied as a new generation of electroelastomers. Fault tolerance is being introduced as a means to prolong operation lifetime. Our projects involve mechanical design, fabrication, and testing of polymer actuators and generators. Bistable electroactive polymer has been introduced for large-strain, rigid-to-rigid actuation. This material is being employed to fabricate Braille electronic readers. Flexible electronics: We are developing electronic devices that are flexible and stretchable. A key component is stretchable transparent electrodes based on composites of carbon nanotubes and silver nanowires. The composites electrodes have sheet resistance and transmission of visible light comparable to indium tin oxide coated on PET and glass. Polymer light emitting diodes and solar cells fabricated on the composite electrodes perform as well as or better than control devices on ITO/glass. Using the composite electrodes, we have demonstrated polymer LEDs wherein the active area is stretchable. Nanostructured hybrid materials: Composites of inorganic compounds and conjugated polymers are prepared with controlled nanostructures for photovoltaics or radiation detection. We synthesized CdS nanorod arrays by electrochemical self-assembly, and CdS thin coating by chemical bath deposition. High-Z nanoparticle polymer composites are studied for gamma and X-ray scintillation. Synthesis of conjugated polymers: The band gap, band edges (electron affinity and ionization potential), optical absorption, photoluminescence color and quantum efficiency, and carrier mobility can be modulated through the conjugated backbone or side chains, structural regularity, molecular weight, purity, and molecular ordering. We can thus tailor conjugated polymers for different applications such as light emitting diodes, solar cells, thin film transistors, and sensors. We fabricate semiconductor devices (LEDs, solar cells) using the selected polymers.

Wu, H.*, Zhu, Y.*, Yan, W.*, Zhang, S., Budiman, W., Liu, K., … & Pei, Q. (2024). A self-regenerative heat pump based on a dual-functional relaxor ferroelectric polymer. Science, 386(6721), 546-551. https://www.science.org/doi/10.1126/science.adr2268 Zhu, Y.; Wu, H.; Martin, A.; Beck, P.; Allahyarov, E.; Wongwirat, T.; Rui, G.; Zhu, Y.; Hawthorne, D.; Fan, J.; Wu, J.; Zhang, S.; Zhu, L.; Kaur, S.; Pei, Q. Operando Investigation of the Molecular Origins of Dipole Switching in P(VDF-TrFE-CFE) Terpolymer for Large Adiabatic Temperature Change. Adv Funct Mater 2024, 2314705, 1–12. https://doi.org/10.1002/adfm.202314705. Yu, H., Winardi, I., Han, Z., Prout, D., Chatziioannou, A. and Pei, Q., Fast Spectroscopic Gamma Scintillation Using Hafnium Oxide Nanoparticles–Plastic Nanocomposites. Chemistry of Materials, 36(1), 533-540 (2023). Han, Z., Peng, Z., Guo, Y., Wang, H., Plamthottam, R. and Pei, Q., Hybrid Fabrication of Prestrain‐locked Acrylic Dielectric Elastomer Thin Films and Multilayer Stacks. Macromolecular Rapid Communications, 2300160 (2023). https://doi.org/10.1002/marc.202300160 Guo, Y., Qin, Q., Han, Z., Plamthottam, R., Possinger, M. and Pei, Q. Dielectric elastomer artificial muscle materials advancement and soft robotic applications. SmartMat, p.e1203 (2023). https://doi.org/10.1002/smm2.1203 Luo, Y., Abidian, M.R., et al., Technology roadmap for flexible sensors. ACS Nano, 17(6), 5211-5295 (2023). Zhao, Y., Wang, B., Tan, J., Yin, H., Huang, R., Zhu, J., Lin, S., Zhou, Y., Jelinek, D., Sun, Z. and Youssef, K., Voisin, L., Horrillo, A., Zhang, K., Wu, B.M., Coller, H.A., Pei, Q., Emaminejad, S., Soft strain-insensitive bioelectronics featuring brittle materials. Science, 378(6625), 1222-1227 (2022). DOI: 10.1126/science.abn5142 Yu, H., Chen, T., Han, Z., Fan, J. and Pei, Q., Liquid Scintillators Loaded with up to 40 Weight Percent Cesium Lead Bromide Quantum Dots for Gamma Scintillation. ACS Applied Nano Materials, 5(10), 14572–14581 (2022). https://doi.org/10.1021/acsanm.2c02930 Shi, Y.,* Askounis, E.,* Plamthottam, R.,* Libby, T., Peng, Z., Youssef, K., Pu, J., Pelrine, R. and Pei, Q., A processable, high-performance dielectric elastomer and multilayering process. Science, 377(6602), 228-232 (2022). DOI: 10.1126/science.abn0099 Han, Z., Yu, H. and Pei, Q., Fluorene Derivatives for Efficient Prompt Scintillation in Plastic Scintillators. ACS Applied Polymer Materials. (2022). DOI: 10.1021/acsapm.2c00391 Pu, J., Meng, Y., Xie, Z., Peng, Z., Wu, J., Shi, Y., Plamthottam, R., Yang, W. and Pei, Q., A unimorph nanocomposite dielectric elastomer for large out-of-plane actuation. Science Advances, 8(9), eabm6200 (2022). DOI: 10.1126/sciadv.abm6200 Gao, M., Meng, Y., Shen, C. and Pei, Q., Stiffness variable polymers comprising phase‐changing side‐chains: material syntheses and application explorations. Advanced Materials, 2109798 (2022). https://doi.org/10.1002/adma.202109798 Mao, P., Shan, X., Li, H., Davis, M., Pei, Q. and Yu, Z., Iontronic Electroluminescence Devices: Comparing Halide Perovskites and Conjugated Polymers. ACS Applied Electronic Materials, 4, 568-575 (2022). Krause, P., Rogers, E., Birowosuto, M.D., Pei, Q., Auffray, E., Vasil’ev, A.N. and Bizarri, G., 2022. Design rules for Time of Flight Positron Emission Tomography (ToF-PET) heterostructure radiation detectors. Heliyon, p.e09754 (2022). Yin, H., Zhu, Y., Youssef, K., Yu, Z. and Pei, Q., Structures and Materials in Stretchable Electroluminescent Devices. Advanced Materials, 2106184 (2021). https://doi.org/10.1002/adma.202106184 Zhang, Y., Zhao, Y., Peng, Z., Yao, B., Alsaid, Y., Hua, M., Wu, D., Qiu, Y., Pei, Q., Zhu, X. and He, X., Ultrastretchable Polyaniline-Based Conductive Organogel with High Strain Sensitivity. ACS Materials Letters, 3, 1477-1483 (2021). Liu, Y., Fan, J., Plamthottam, R., Gao, M., Peng, Z., Meng, Y., He, M., Wu, H., Wang, Y., Liu, T. and Zhang, C., Pei, Q. Automatically Modulated Thermoresponsive Film Based on a Phase-Changing Copolymer. Chemistry of Materials. 33 (18), 7232–7241 (2021). Shi, X., Zuo, Y., Zhai, P., Shen, J., Yang, Y., Gao, Z., Liao, M., Wu, J., Wang, J., Xu, X., Tong, Q., Zhang, B., Wang, B., Sun, X., Zhang, L, Pei, Q., Jin, D., Chen, P., Peng, H., Large-area display textiles integrated with functional systems. Nature, 591(7849), 240-245 (2021). Gao, M., Wu, H., Plamthottam, R., Xie, Z., Liu, Y., Hu, J., Wu, S., Wu, L., He, X. and Pei, Q., Skin temperature-triggered, debonding-on-demand sticker for a self-powered mechanosensitive communication system. Matter. 4, 1-13 (2021). https://doi.org/10.1016/j.matt.2021.03.003 Meng, Y., Pu, J. and Pei, Q., Electrocaloric cooling over high device temperature span. Joule, 5, 1-14 (2021). https://doi.org/10.1016/j.joule.2020.12.018 Zhao, H., Yu, H., Redding, C., Li, Z., Chen, T., Meng, Y., Hajagos, T.J., Hayward, J.P. and Pei, Q., Scintillation Liquids Loaded with Hafnium Oxide Nanoparticles for Spectral Resolution of γ Rays. ACS Applied Nano Materials. 4, 1220-1227 (2021). Chen, T., Yu, H., Wen, X., Redding, C., Hajagos, T.J., Zhao, H., Hayward, J.P., Yang, C. and Pei, Q., A Plastic Scintillator Based on an Efficient Thermally Activated Delayed Fluorescence Emitter 9‐(4‐(4, 6‐diphenyl‐1, 3, 5‐triazin‐2‐yl)‐2‐methylphenyl)‐3, 6‐dioctyl‐9H‐carbazole for Pulse Shape Discrimination Measurement. Advanced Optical Materials, https://doi.org/10.1002/adom.202001975 (2021). Wang, W., Du, L., Xie, Y., Zhang, F., Li, P., Xie, F., Wan, X., Pei, Q., Leng, J. and Wang, N., Bioinspired four-dimensional polymeric aerogel with programmable temporal-spatial multiscale structure and functionality. Composites Science and Technology, 206, 108677 (2021). https://doi.org/10.1016/j.compscitech.2021.108677 Peng, Z., Shi, Y., Chen, N., Li, Y. and Pei, Q., Stable and High‐Strain Dielectric Elastomer Actuators Based on a Carbon Nanotube‐Polymer Bilayer Electrode. Advanced Functional Materials, 31(9), 2008321 (2020). https://doi.org/10.1002/adfm.202008321 Meng, Y., Zhang, Z., Wu, H., Wu, R., Wu, J., Wang, H. and Pei, Q., A cascade electrocaloric cooling device for large temperature lift. Nature Energy, 5, 996–1002 (2020). DOI: https://doi.org/10.1038/s41560-020-00715-3. Guan, F., Xie, Y., Wu, H., Meng, Y., Shi, Y., Gao, M., Zhang, Z., Chen, S., Chen, Y., Wang, H. and Pei, Q., Silver Nanowire–Bacterial Cellulose Composite Fiber-Based Sensor for Highly Sensitive Detection of Pressure and Proximity. ACS Nano. 14, 15428-39 (2020). Haque, A.T., Tutika, R., Gao, M., Martinez, A., Mills, J.M., Clement, J.A., Gao, J., Tabrizi, M., Shankar, M.R., Pei, Q. and Bartlett, M.D., Conductive liquid metal elastomer thin films with multifunctional electro-mechanical properties. Multifunctional Materials, 3(4), 044001 (2020). DOI: https://doi.org/10.1088/2399-7532/abbc66 Zhao, Y., Zhang, B., Yao, B., Qiu, Y., Peng, Z., Zhang, Y., Alsaid, Y., Frenkel, I., Youssef, K., Pei, Q. and He, X., Hierarchically Structured Stretchable Conductive Hydrogels for High-Performance Wearable Strain Sensors and Supercapacitors. Matter, 3(4), 1196-1210 (2020). Youssef, K., Li, Y., O’Keeffe, S., Li, L. and Pei, Q., 2020. Fundamentals of Materials Selection for Light‐Emitting Electrochemical Cells. Advanced Functional Materials, 30, 1909102 (2020). https://doi.org/10.1002/adfm.201909102 Pei, Q., Costa, R., Editorial: 25 Years of Light‐Emitting Electrochemical Cells. Advanced Functional Materials, 30, 2002879 (2020). doi: 10.1002/adfm.202002879 Li, Y.F., Liu, X., Feng, J., Xie, Y., Zhao, F., Zhang, X.L., Pei, Q. and Sun, H.B., Highly transparent and conductive metal oxide/metal/polymer composite electrodes for high-efficiency flexible organic light-emitting devices. Nanophotonics, 1, (2020). https://doi.org/10.1515/nanoph-2020-0214. Xie, Y., Guan, F., Li, Z., Meng, Y., Cheng, J., Li, L. and Pei, Q., 2020. A Phase‐Changing Polymer Film for Broadband Smart Window Applications. Macromolecular Rapid Communications, 2000290 (2020). DOI: 10.1002/marc.202000290 Qiu, Y., Askounis, E., Guan, F., Peng, Z., Xiao, W. and Pei, Q., 2020. Dual-Stimuli-Responsive Polymer Composite with Ultrawide Tunable Stiffness Range Triggered by Water and Temperature. ACS Applied Polymer Materials, 2(5), 2008-2015 (2020). https://doi.org/10.1021/acsapm.0c00181 Wang, H., Meng, Y., Zhang, Z., Gao, M., Peng, Z., He, H. and Pei, Q., Self‐Actuating Electrocaloric Cooling Fibers. Advanced Energy Materials, 10, 1903902 (2020). https://doi.org/10.1002/aenm.201903902 Cheng, J., Wang, S., Tang, Y., Hu, R., Yan, X., Zhang, Z., Li, L. and Pei, Q., Intensification of Vertical Phase Separation for Efficient Polymer Solar Cell via Piecewise Spray Assisted by a Solvent Driving Force. Solar RRL, 4(3), 1900458 (2020). https://doi.org/10.1002/solr.201900458 ​ Zhang, Z., Alwen, A., Lyu, H., Liu, X., Li, Z., Xie, Z., Xie, Y., Guan, F., Babakhani, A. and Pei, Q., Stretchable transparent wireless charging coil fabricated by negative transfer printing. ACS applied materials & interfaces, 11(43), pp.40677-40684 (2019). Zhang, Y., Zhao, Y., Wu, D., Xue, J., Qiu, Y., Liao, M., Pei, Q., Goorsky, M.S. and He, X., 2019. Homogeneous Freestanding Luminescent Perovskite Organogel with Superior Water Stability. Advanced Materials, 31(37), 1902928 (2019). Qiu, Y., Ma, S., Pei, Q. and Holbery, J.D., 2019. A Self‐Conformable Smart Skin with Sensing and Variable Stiffness Functions. Advanced Intelligent Systems, 1, p.1900054 (2019) Hajagos, T.J., Garcia, E., Kishpaugh, D. and Pei, Q., Plastic scintillators based on thermally activated delayed fluorescence dyes. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 940, 185-198 (2019). Li, Y.F., Chou, S.Y., Huang, P., Xiao, C., Liu, X., Xie, Y., Zhao, F., Huang, Y., Feng, J., Zhong, H. and Sun, H.B., Pei, Q., Stretchable Organometal‐Halide‐Perovskite Quantum‐Dot Light‐Emitting Diodes. Advanced Materials, 31, 1807516 (2019). Qiu, Y., Zhang, E., Plamthottam, R. and Pei, Q., Dielectric Elastomer Artificial Muscle: Materials Innovations and Device Explorations. Accounts of Chemical Research, 52 (2), 316-325 (2019). Ma, R., Chou, S. Y., Xie, Y., & Pei, Q. (2019). Morphological/nanostructural control toward intrinsically stretchable organic electronics. Chemical Society Reviews. DOI: 10.1039/C8CS00834E Li, Y. F., Chou, S. Y., Huang, P., Xiao, C., Liu, X., Xie, Y., … Sun, H. B. & Pei, Q. (2019). Stretchable Organometal‐Halide‐Perovskite Quantum‐Dot Light‐Emitting Diodes. Advanced Materials, 1807516. https://doi.org/10.1002/adma.201807516 Qiu, Y., Zhang, E., Plamthottam, R., & Pei, Q. (2019). Dielectric Elastomer Artificial Muscle: Materials Innovations and Device Explorations. Accounts of chemical research. https://doi.org/10.1021/acs.accounts.8b00516 Peng, Z., Qiu, Y., Shi, Y., Zhang, Z., Alwen, A., Yin, H., … & Pei, Q. (2019, March). Bistable electroactive polymers for refreshable tactile displays. In Electroactive Polymer Actuators and Devices (EAPAD) XXI (Vol. 10966, p. 109662C). International Society for Optics and Photonics. https://doi.org/10.1117/12.2513780 Li, Y. F., Chou, S. Y., Huang, P., Xiao, C., Liu, X., Xie, Y., … Sun, H. B. & Pei, Q. (2019). Quantum Dot LEDs: Stretchable Organometal‐Halide‐Perovskite Quantum‐Dot Light‐Emitting Diodes (Adv. Mater. 22/2019). Advanced Materials, 31(22), 1970157. https://doi.org/10.1002/adma.201970157 Hamedi, M. M., Herland, A., Zhang, F., & Pei, Q. (2019). Organic Polymer Electronics–A Special Issue in Honor of Prof. Olle Inganäs. Advanced Materials, 31(22), 1901940. https://doi.org/10.1002/adma.201901940 Hajagos, T. J., Garcia, E., Kishpaugh, D., & Pei, Q. (2019). Plastic scintillators based on thermally activated delayed fluorescence dyes. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. https://doi.org/10.1016/j.nima.2019.05.095