A Monolithic Electrostatic–Hydraulic Coupled Suction Pad

Abstract

Suction cups are one of the most widely adopted switchable adhesive techniques and play a crucial role in manufacturing and robotics. However, conventional negative pressure sources (e.g., diaphragm vacuum pumps) suffer from poor scalability from meso- to microscale, unavoidable vibration and noise, while the performances of existing smart material-driven suction cups are often restricted by their bulky structures, poor active adhesive stresses, or high power consumptions. To address these limitations, a monolithic suction pad is proposed where its active adhesion is realized by the electrostatic–hydraulic coupling generated negative pressure cavity and the sealing is achieved by the elastomeric–hydraulic coupled outer rim. This suction pad features a peak pull-off stress of 7.4 kPa and good switch ability in its adhesive stress of over 12 times. Compared with the existing smart material-driven suction cups, the proposed suction pad demonstrates clear advantages in its significantly lower profile structure, lower preload stress requirement, and a higher adhesive force to power consumption ratio. This suction pad is envisioned to have promises in broad applications such as digital manufacturing, transfer printing, medical robotics, and robotic locomotion.