We experimentally demonstrated formation of electrically conductive structures by modifying native polydimethylsiloxane (PDMS) with femtosecond laser. By irradiating femtosecond laser pulses to native PDMS, black structures with electrical conductivity were formed. Analyses using X-ray diffraction (XRD) show that the formed structures were composed of β-silicon carbide (β-SiC). Our technique enables the spatially selective formation of β-SiC on the surface of PDMS, leading to open a novel route to develop a simple method to fabricate flexible or stretchable MEMS devices with SiC microstructures.
By femtosecond-laser-based modification of polydimethylsiloxane (PDMS), we fabricated an electrically conductive structure composed of β-silicon carbide (β-SiC) on a PDMS thin film for strain sensing. With an increase in applied strain, i.e. smaller bend radii of the conductive structures, the conductivity of the structure decreased significantly. The result indicates that the resistance of the conductive structure has high sensitivity to strain, leading to potential applications such as real-time monitoring of human motion.