A Monolithic Electrostatic-Hydraulic Coupled Suction Pad

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.