Dr. Qibing Pei    Professor Qibing Pei
Tel. (310) 825-4217
FAX (310) 206-7353

Professor: Ph.D. 1990 Chinese Academy of Sciences, Beijing.  Stretchable Polymer Electronics; Conjugated polymers; Electroactive polymer artificial muscles; Nanostructured materials; Polymer actuators and generators; Radiation detection; Polymer synthesis; Polymer composite.

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.  


Research Interests

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. 

Area of Thesis Guidance

Electronic polymer synthesis, electroactive polymer artificial muscles, polymer actuators, polymer electronic devices.


Prospective graduate students and postdoctoral researchers with the following specialties are welcome to apply: synthesis of conjugated polymers; solution-based nanofabrication; polymer processing; thin film electronic devices; organic synthesis; actuators and sensors.

We anticipate multiple postdoctoral openings to develop dielectric elastomers for muscle-like actuation, stretchable polymer electronics, and solution-based coating of polymeric and nanomaterials.  Candidates with strong hands-on experience in at least three of these fields are encouraged to apply:  synthesis of nanocomposites (e.g. graphene nanocomposites), synthesis of conjugated polymers, nanomaterials processing, polymer coating, solution processing of carbon nanotubes and graphene, slot die coating, soft polymer actuator fabrication, high thermal conductive materials, characterization of thermal conductivity.


Recent Publications


  • C. Murray, D. McCoul, E. Sollier, T. Ruggiero, X. Niu, Q. Pei, D. Di Carlo, “Electro-adaptive microfluidics for active tuning of channel geometry using polymer actuators”,  Microfluidics and Nanofluidics, 14(1), 345-358 (2013).

  • H. Stoyanov, P. Brochu, X. Niu, C. Lai, S. Yun and Q. Pei, “Long lifetime, fault-tolerant freestanding actuators based on a silicone dielectric elastomer and self-clearing carbon nanotube compliant electrodes,” RSC Advances, 3 (7), 2272 – 2278 (2013).

  • X. Niu, H. Stoyanov, W. Hu, R. Leo, P. Brochu,
    Q. Pei, “Synthesizing a New Dielectric Elastomer Exhibiting Large Actuation
    Strain and Suppressed Electromechanical Instability without Prestretching”, J.
    Polymer Science, Part B: Polymer Physics, 51, 197–206 (2013).

  • L. Li, J. Liu, Z. Yu, Q. Pei, “Efficient White
    Polymer Light-Emitting Diodes Employing a Silver Nanowire-Polymer Composite
    Electrode”, Phys. Chem. Chem. Phys., 14 (41), 14249 – 14254 (2012).

  • W. Hu, X. Niu, L. Li, S. Yun, Z. Yu, and Q. Pei,
    “Intrinsically stretchable transparent electrodes based on
    silver-nanowire–crosslinked-polyacrylate composites”, Nanotechnology 23, 344002

  • H. Stoyanov, P. Brochu, X, Niu, E.D. Gaspera, Q.
    Pei, “Dielectric elastomer transducers with enhanced force output and work
    density”, Applied Physics Letters, 100, 262902 (2012).

  • S. Yun, X. Niu, Z. Yu, W. Hu, P. Brochu, Q. Pei,
    “Compliant Silver Nanowire-Polymer Composite Electrodes for Bistable Large
    Strain Actuation”, Advanced Materials, 24, 1321-1327 (2012).

  • L. Li, Z. Yu, W. Hu, C.-H. Chang, Q. Chen and Q.
    Pei, “Efficient Flexible Phosphorescent Polymer Light-Emitting Diodes Based on
    Silver Nanowire-Polymer Composite Electrode”, Advanced Materials, 23(46),
    5563–5567 (2011).

  • Z. Yu, L. Li, Q. Zhang, W. Hu, Q. Pei, “Silver
    Nanowire-Polymer Composite Electrodes for Efficient Polymer Solar Cells”,  Adv Mater. 23(38), 4453-4457 (2011).

  • Z. Yu, X. Niu, Z. Liu, Q. Pei, “Intrinsically
    Stretchable Polymer Light-Emitting Devices Using Carbon Nanotube-Polymer
    Composite Electrodes”, Adv. Mater. 23 (34), 2011, 3989–3994 (2011).

  • J. Liu, L. Li, C. Gong, Z. Yu, Q. Pei, “An
    Ambipolar Poly(Meta-Phenylene) Copolymer with High Triplet Energy to Host Blue
    and Green Electrophosphorescence”, J. Mater. Chem., 21, 9772-9777 (2011).

  • L. Li, J. Liu, Z. Yu, and Q. Pei, “Highly
    Efficient Blue Phosphorescent Polymer Light-Emitting Diodes by Using
    Interfacial Modification”, Appl. Phys. Lett. 98 (20), Article No: 201110 (May

  • L. Li, J. Liu, Z. Yu, and Q. Pei, “Highly
    Efficient Blue Phosphorescent Polymer Light-Emitting Diodes by Using
    Interfacial Modification”, Appl. Phys. Lett. 98 (20), Article No: 201110 (2011).

  • J. Liu, L. Li, Q. Pei, “Conjugated Polymer as
    Host for High Efficiency Blue and White Electrophosphorescence”,
    Macromolecules  44 (8),  2451-2456 (2011).

  • Z. Yu, M. Wang, G. Lei, J. Liu, L. Li, Q. Pei, “Stabilizing
    the Dynamic p-i-n Junction in Polymer Light-Emitting Electrochemical Cells”, J.
    Phys. Chem. Lett. 2, 367-372 (2011).

  • Z. Yu, Q. Zhang , L. Li , Q. Chen , X. Niu , J.
    Liu , and Q. Pei, “Highly Flexible Silver Nanowire Electrodes for Shape-Memory
    Polymer Light-Emitting Diodes,” Adv
    Mater. 23, 664-668 (2011).

  • J. Liu, Q. Pei, “Poly(m-phenylene): Conjugated
    Polymer Host with High Triplet Energy for Efficient Blue Electrophosphorescence,”
    Macromolecules, 43, 9608-9612 (2010).

  • J. Liu, Q. Pei, “Electrophosphorescent Polymers
    for High-Efficiency Light-Emitting Diodes,” Current Org. Chem. 14, 2133-2144

  • W. Yuan, H. Li, P. Brochu, X. Niu and Q. Pei,
    “Fault-tolerant silicone dielectric elastomers”, International J. Smart and
    Nano Materials, Vol. 1, No. 1, pp 40–52 (2010).

  • H. Zhang, L. Düring, G. Kovacs, W. Yuan, X. Niu,
    Q. Pei, “Interpenetrating polymer networks based on acrylic elastomers and
    plasticizers with improved actuation temperature range”, Polymer International,
    59, 384-390 (2010.

  • P. Brochu, Q. Pei, “Advances in Dielectric
    Elastomers for Actuators and Artificial Muscles,” Macromol. Rapid Commun. 2010,
    31, 10-36 (2010).

  • Z. Yu, W. Yuan, P. Brochu, B. Chen, Z. Liu, Q.
    Pei, “Large-strain, Rigid-to-rigid Deformation of Bistable Electroactive Polymers”,
    Appl. Phys. Lett. 95, 192904 (2009).

  • Z. Yu, L. Hu, Z. Liu, M. Sun, M. Wang, G.
    Grüner, Q. Pei, “Fully Bendable Polymer Light Emitting Devices with Carbon
    Nanotubes as Cathode and Anode,” Appl. Phys. Lett. Vol. 95, #203304, pp 1-3

  • W. Yuan, P. Brochu, S.M. Ha, Q. Pei, “Dielectric
    Oil Coated Single-walled Carbon Nanotube Electrodes for Stable, Large-strain
    Actuation with Dielectric Elastomers”, Sensors and Actuators A: Physical, Vol. 155,
    pp 278–284 (2009).


  • Q. Pei, “Forward”,
    Iontronics: Ionic Carriers in Organic Electronic Materials and Devices.
    Editor(s):  J. Leger, M. Berggren, S.
    Carter, CRC Press. Published Oct. 14, 2010.

  • Y. Li, Q. Pei, “Electrochemistry of Conjugated Polymers”, Iontronics: Ionic
    Carriers in Organic Electronic Materials and Devices. Editor(s):  J. Leger, M. Berggren, S. Carter, CRC Press.
    Published Oct. 14, 2010.

  • S.M. Ha, Q. Pei, R. Pelrine, S. Stanford, “Interpenetrating Polymer Networks as High
    Performance Dielectric Elastomers,”
    in “Dielectric Elastomers as
    Electromechanical Transducers: Fundamentals, materials, devices, models &
    applications of an emerging electroactive polymer technology.” Eds. F. Carpi,
    D. DeRossi, R. Kornbluh, R. Pelrine, P. Sommer-Larsen, Chapter 5. Publisher:
    Elsevier, January 2008.

  • M. Rosenthal, Q. Pei, “Multiple-degrees-of-freedom Roll Actuators,” in “Dielectric
    Elastomers as Electromechanical Transducers: Fundamentals, materials, devices,
    models & applications of an emerging electroactive polymer technology.” Eds.
    F. Carpi, D. DeRossi, R. Kornbluh, R. Pelrine, P. Sommer-Larsen, Chapter 9. Publisher:
    Elsevier, January 2008. 

Professional Activities

  • Scientific Advisory Board, Annual Conferences of Electroactive Polymer Actuators and Materials, since 2006.

  • Scientific Committee member, International Conference on Smart Materials and Nanotechnology in Engineering, since 2008.

  • Member, California NanoSystems Institute, UCLA, since 2006.

  • Faculty member, Materials Creation Training Program, UCLA, since 2006.

  • Members of MRS and ACS

  • Fellow of SPIE.



Research Group/Lab:


Courses Taught

MSE 104  Science of Engineering Materials
MSE 150  Introduction to Polymers
MSE 251  Chemistry of Soft Materials
MSE 252  Organic Polymer Electronic Materials

Office Location

3121-H Engineering V

Mailing Address

UCLA, HSSEAS School of Engineering & Applied Sciences
Department of Materials Science and Engineering
410 Westwood Plaza
3111 Engineering V
Los Angeles, CA 90095-1595