Auxetic bipolar electrostatic chuck for conformal attachment of large-area flexible films to nonplanar targets

Demand for flexible electronics and wearable devices has increased the need to handle large-area flexible films and delicate planar objects on doubly curved surfaces. Although conventional electrostatic chucks provide constant adhesion with uniformly distributed pressure for an applied voltage, their flat surfaces cannot conform to curved geometries without a significant loss of adhesive force, limiting their applicability to large-area and high-curvature surfaces. We developed a bipolar electrostatic chuck incorporating an auxetic structure to enable continuous gripping and conformal transfer of films to nonplanar targets and experimentally evaluated its characteristics. We fabricated a functional prototype by assembling 3D-printed polymer parts to integrate electrodes within a flexible grid-shaped auxetic frame. This design utilizes the negative Poisson’s ratio of the auxetic structure to transform a planar surface into a synclastic curvature while maintaining an appropriate interelectrode spacing during deformation. The deformability of the device was verified through finite-element simulations and experimental profile measurements. The generated electrostatic forces were measured using an electric balance, and the forces in the planar and curved states were compared to evaluate the effectiveness of conformal contact. Two collaborative robotic arms successfully performed a continuous handling sequence in which a film was gripped, deformed, placed onto a hemispherical surface, and released. These results demonstrate the potential of the proposed device for continuous gripping and conformal transfer on curved surfaces in future manufacturing technologies.