The elastic microstructures of inkjet printed polydimethylsiloxane as the patterned dielectric layer for pressure sensors

A direct inkjet printing process was developed to fabricate patterned elastic microstructures for pressure sensors using n-butyl acetate diluted polymethylsiloxane (PDMS). The diluted PDMS precursor mixture with a cross-linker exhibited a controllable viscosity below 14 cP in 48 h at 25 °C, and the PDMS film had lower elastic modulus and hardness values than the non-diluted PDMS precursor after curing. The capacitor using the printed PDMS film as the microstructured dielectric layer showed a very high pressure sensitivity of up to 10.4 kPa−1 under the pressure below 70 Pa, and the pressure sensitivity would be dramatically decreased to 0.043–0.052 kPa−1 under the pressure between 2 and 8 kPa. Furthermore, the triboelectric sensors could be structured with an inkjet printed PDMS film and controllably generate the voltage signals up to 1.23 V without any amplification. The results suggest that mechanical properties and patterned elastic microstructures play the key roles in PDMS-based sensor devices, and th...