Controllable Particle Adhesion with a Magnetically Actuated Synthetic Gecko Adhesive

Particle capture and release using controllable adhesion is of growing interest in many fields including reusable adhesives, solar panel cleaning, micro-manipulation and robot locomotion where current methods of particle management are not sufficient. Here controllable adhesion to glass spheres with a new magnetically actuated synthetic gecko adhesive made from a magnetoelastomer composite is demonstrated. Adhesion is controlled by changing the effective elastic modulus of the surface through actuation of micro surface features with an external magnetic field. A compliant mechanics and magnetic torque analysis explains this general principle and generalizes the results for various geometries. Results show sphere pull-off forces can be increased 10-fold by changing the ridge orientation via the external magnetic field, and that the effective elastic modulus can be changed from 65 kPa to 1.5 MPa. Particle transport and release of 500- and 1000-micrometer glass spheres is also demonstrated.