Tunable Adhesion

Turning adhesion on or off to open new possibilities for process control

Problem:

Advanced manufacturing processes require methods to delicately handle fragile materials. Certain materials are too compliant and brittle to transfer them with vacuum or mechanical handling, and traditional adhesives may leave behind an unacceptable residue.

Some researchers have experimented with bio-inspired adhesion, but these systems are difficult to apply on an industrial scale. A way to temporarily adhere to surfaces during assembly would open up new methods of manufacturing for semiconductors, electronics, and other products.

Solution:

Researchers at the University of Pennsylvania have developed a new tunable composite material with high adhesion under normal loading and weak adhesion when shear is applied, making the surface adhesion easily controllable.

A micro-scale composite structure is patterned using a stiff post surrounded by a compliant core. A contact surface made up of an array of these posts has strong adhesion in the normal direction but can be easily removed by applying a shear force. This makes manipulation of thin layers of delicate material possible, because no damaging handling forces are applied, and no residue is left behind.

Adhesive contact surfaces that use this method can easily be produced on a large scale, making this technology a practical solution as an applied process improvement.

Advantages: