Remotely Controlled Microscale 3D Self-Assembly Using Microwave Energy

A novel, remotely controlled assembly process is developed to create microscale, self-assembled 3D structures using remote-controlled microwave energy. A nanometer thick chromium (Cr) film absorbs electromagnetic microwaves and generates heat energy, which induces reflow of polymeric hinges. This leads to self-assembly of microscale 3D cubic structures. Since this assembly process does not require direct contact with a heat source or chemicals, microscale actuations can be achieved in a remote location without physical contact, resulting in the powerful capability to manipulate the 3D assembly process in situations where the heat sources and the environment around the microstructures are not controllable and accessible. Multiple folding configurations of the microstructures can also be achieved simultaneously with a single microwave energy source by forming different Cr thicknesses adjacent to the polymer hinges. Thus, remote-controlled selfassembly using microwave energy might be applied for the development of 3D microscale-sensors, -microbots, and -metamaterials.