Surface switches

The surface switches Acreo are working on are based on conducting polymers and have the possibility to change its surface properties. When a potential is applied to the conducting polymer it undergoes an electrochemical reaction that results in either a reduced or oxidised material, which for most polythiophenes result in different wettability. The wettability change of the polymer can be used to guide a liquid in a microfluidic system. The redox switch of the conducting polymer can also result in conformation changes for the adhered proteins on the surface.

The left image shows an injection moulded surface switch, while the right image illustrates the difference in wettability on the reduced and oxidised surfaces of a conducting polymer.