Asymmetric Capacitive Pixel Array (E-CaP) for Mapping of Epidermal Vectored Movement

We demonstrate a
$3\times3$
epidermal asymmetric capacitive pixel (E-CaP) array with direction-sensitive capabilities. The conformally laminated E-CaP has a capacitive sensing mechanism and effectively maps the direction and the pressure of epidermal movements. The difference in the previously retained and the present value of the response represents the rate of change of capacitance. This rate of change per unit displacement is crucial to determine the vectored response of the strain-induced in the E-CaP. The nominal capacitance of the array is ~3.370 pF and shows a prominent change (
$\vec {d)}$
of
$1.341\hat {i}+2.007\hat {j}+8.750\hat {k}$
pF/mm. The micromeshed (
$\mu $
-meshed) polydimethylsiloxane (PDMS) structure is fabricated using SU-
$8 ~\mu $
-mold and is sandwiched between the asymmetric electrodes. The
$\mu $
-meshed design offers greater shear displacement, allowing the E-CaP to move conformally with the skin. The possible movement domain associated with the limbs that are laminated with E-CaP can map the entire generated vector response (directional specific). The E-CaP is simulated and tested for mapping the directional sensitive epidermal movement.