Transferrable Ultrathin Polypyrrole Composite Films

Transferrable and highly conductive polymeric films capable of maintaining macroscale conductivity at a thickness below 100 nm

The Need

Conducting polymer (CP) films, including polypyrrole (PPy), polyaniline (PANI) and poly (3,4-ethylene dioxythiophene) (PEDOT), are generally non-transferrable as their thickness declines to 200 nm or less, which causes difficulty in detaching them from the initial substrate after electropolymerization and transferring to other bases. Electrochemical polymerization (ECP) has served as the standard fast approach to fabricate mechanically robust CP films of well-controlled thickness and redox-alterable surface characteristics. A smaller thickness is vital to enhance conformability of CP-based interfaces for better interfacing with soft tissues like brain and muscle, however, following whatever approaches available so far, post-synthesis transfer of ultrathin CP films (e.g. thickness below 200 nm) has been extremely difficult. This technical barrier not only precludes numerous potential applications but severely restrains our knowledge on how to maintain macroscopic conductance at nano-thick CP films. Thus, there is a strong need for ultrathin and highly conductive CP films that can be easily transferred in a contamination and distortion free manner.

The Technology

Bingxi Yan has developed a family of electropolymerized ultrathin PPy composite films that can be easily transferred in water to diverse bases, in a manner free from contamination or mechanical distortion. These transferrable PPy films are capable of maintaining a high conductivity over ~85 S/cm even at a thickness below 100 nm. The films are inherently water-responsive, detaching themselves instantly from the substrate in water and therefore can be easily transferred without resorting to any other chemical or physical treatment - fast and in seconds. The successful combination of high transferability, conductivity, biocompatibility, and transparency is unique and unavailable from any other known CP materials, which paves the way to future designs of ultraconformal CP bio-interfaces and cell-engineering electrodes.

Commercial Applications

  • Bioelectronics
  • Medical Devices


  • Easily transferrable via ECP
  • Conductive on the macroscale
  • Thickness of less than 100 nm
  • Good biocompatibility
  • Mechanically robust

Research Interest

The Laboratory for Transplantable Biocircuits at The Ohio State University, led by Dr. Liang Guo, is pioneering the science and engineering of biological circuits, devices and embedded systems for biomedical research and medical applications. A highly interdisciplinary area, application-specific integrated biocircuits (ASIbioCs) are the biological implementation of the ASIC concept using living cells and customized for particular biomedical applications. Fundamental approaches for ASIbioCs include, but not limited to, microfabrication, tissue engineering, biomaterials, stem cell biology, synthetic biology, and developmental engineering.

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