Ultra-Thin CNT/PDMS Nanocomposite Sponge for Pressure Sensing and Acoustic Wave Generation

Polymer nanocomposites reinforced by conductive nanofiller has attracted much attention due to their enhanced mechanical and electrical properties. We have developed an ultrathin (~400µm) sponge structure with carbon nanotube/polydimethylsiloxane (CNT/PDMS) nanocomposites with adjustable electrical/mechanical properties tunable by changing the CNT concentration in the composite material. In particular, the nanocomposite sponge with low CNT concentration (i.e., CNT: PDMS weight ratio of 3%) was demonstrated to be applicable as a skin-attachable sensor for human physiological signal monitoring due to its biocompatibility and good pressure sensitivity. On the other hand, the sponge nanocomposite with a high CNT concentration (i.e., CNT: PDMS weight ratio of 30%) can be applied as a flexible acoustic wave generator based on the thermoacoustic effect. The fabrication process for this nanocomposite sponge material and various example applications of this material are presented in this paper.