Journal Article

Scalable High‐Force Zipping Electrostatic Actuators

Caruso, Fabio, Shea, Herbert, Firouzeh, Amir

2026

Overview

Electrostatic actuators are well suited for integration in soft and wearable robotics due to their speed, energy efficiency, self‐sensing, and direct electrical drive. Although electrostatic actuation has a high theoretical energy density when considering only the thin active area, generating forces and strokes suited for wearable robotics while simultaneously reaching muscle‐like energy density has been a challenge. We introduce here the honeycomb electrostatic zipping actuator, a scalable actuator comprising dozens to hundreds of millimeter‐scale electrostatic zipping units, obtained by repeatedly folding a patterned sheet. The series–parallel arrangement allows independently tuning force and stroke. We thus have the high energy density of thin film devices, while also obtaining forces and strokes suitable for many robotic tasks. We report energy density of over 28 J/kg and forces of over 40 N for a device with an active volume of 3.8 cm 3 . We derived an analytical model that accurately predicts actuator performance without fitting parameters, serving as a rational design tool. We developed a fabrication approach based on bonded metalized polyimide sheets, enabling rapid assembly of multi‐cell actuator arrays. This approach establishes a practical path toward scalable, high‐performance electrostatic actuators for soft robotics applications.