Low-voltage Electroadhesive Pad with Thin Insulation Layer Fabricated by Parylene Deposition

Electroadhesion has a large potential to be extensively used due to its advantages such as lightweight, strong force, and flexibility, but the high excitation voltage (usually more than 1.5 kV) bottle-necks its broad applications. Although increasing the dielectric constant is promising, the dielectric strength and tensile strength become lower simultaneously. Reducing the insulation layer thickness is another possible approach to lower the voltage, but previous fabrication methods and materials do not support this way. This work implants the parylene coating method, which is well-developed in semiconductor industry, into the fabrication of thin insulation layer of the electroadhesive pads. A pad with 7 μm thin insulation layer is demonstrated, and it can generate comparably strong force under 340 V while previous polymer-based insulation requires more than 1.5 kV voltage. For the thin insulation layer, air gap becomes noticeable, and its effects are experimentally studied and analyzed.