Flexible distributed capacitive sensor with encapsulated ferroelectric liquid

We demonstrate flexible and highly sensitive capacitive sensor arrays that encapsulate DI water as dielectric. DI water, which is a ferroelectric liquid and has a relative dielectric constant of approximately 80, could increase the capacitance of the sensor and enhance the sensitivity while maintaining flexibility of the sensor with electrodes patterned on flexible PDMS substrates. The proposed sensor was microfabricated and demonstrated successfully 40 times greater sensitivity than sensors without DI water. Since DI water is incompressible fluid, it restricted the displacements of the electrodes. We designed a reservoir of DI water where the DI water between the electrodes could escape, which allowed more deformation of the PDMS substrates and successfully augmented the sensitivity of the proposed sensor.