A. Palumbo, R. Zhang, K. Yan, S. Chen, G. Hader, J. Chang, E.H. Yang
Stevens Institute of Technology,
Keywords: flexible electronics, pressure sensor, carbon nanotubes, PDMS
Summary:Flexible electronics has directed development and research of unique instrumentation and measurement techniques to achieve conformable sensors for a wide range of applications . Conventional high-performance electronic materials such as silicon are not flexible, whereas many flexible materials, such as conducting polymers, are often characterized by poor electric properties . Thus, high mobility materials in a flexible configuration are desirable, and carbon nanotubes (CNTs) are promising owing to their excellent electronic properties and flexibility owing to their small diameter. Here, we present a flexible and stretchable pressure sensor composed of vertically aligned CNTs (VACNTs) partially embedded in a polydimethylsiloxane (PDMS) substrate. VACNTs were grown via chemical vapor deposition and transferred onto PDMS as a stretchable electrode. Two such electrodes were placed face-to-face. Here, increased pressure is directly proportional to a detectable change in resistance, enabled by increased contact between the opposing electrode surfaces. The measured resistance was maintained at stretching up to 180%, with a rapid response time during loading and unloading. As a proof-of-concept, the sensor was successfully tested for measuring biological signals of a person. This work will directly impact the development of pressure sensing devices toward medical and e-skin applications. References  Wong, W. S. & Salleo, A. Flexible electronics: materials and applications. 11, (Springer Science & Business Media, 2009).  Nyholm, L., Nyström, G., Mihranyan, A. & Strømme, M. Adv. Mater. 23, 3751–3769 (2011).