An ultrathin conformal, MoS2 -based tactile sensing array covering an area of 2.2 cm -2.2 cm was demonstrated. The sensor was integrated with a graphene electrode and interconnect to achieve good mechanical flexibility and optical transmittance in the visible color range. First, graphene grown by the chemical vapor depostion (CVD) method was transferred to a SiO2/Si handling wafer coated with SU-8 epoxy and patterned to shape electrodes with interdigitated geometry and interconnects. Next, MoS2 was printed on the graphene electrodes and patterned it using photolithography and CHF33/O2 plasma. The device was separated from the handling wafer to produce a freestanding film for fabrication of conformal devices on unusual substrates. Compressive and tensile loads were conducted using a bending machine to induce strain in the MoS2 strain gauge ranging from -1.98% to 1.98% with 36 steps in 16 cells. The MoS2 strain sensor exhibited a variety of advantages, such as good optical transparency, mechanical flexibility, and high GF, compared with conventional strain gauges. In particular, ultrathin nature of the device enabled to create it on unusual substrates, such as a fingertip or leather products. Furthermore, this prototype of the conformal MoS2 tactile sensor can be utilized to achieve a high integration density array, low crosstalk, and high switching speed through active matrix circuitry.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering