Vacuum process opens microfluidic applications for liquid metal

The research by engineers from North Carolina State University is said to address two of the most common difficulties in creating liquid metal-filled microchannels.

Liquid metals are promising as soft, stretchable electrical components such as antennas, circuits, electrodes and wires but these applications often require the ability to pattern the liquid metal into different and sometimes complicated shapes at scales smaller than 100 microns. This is done by pushing the liquid metal into microchannels, which are small, hollow, tube-like structures within a flexible elastomer material.

The patterns are usually created via injection, pushing the metal into the channels via an inlet. The pressure required to push the metal into the microchannel can cause the channels to rupture and leak. Furthermore, to completely fill the channel, the air trapped within it must be vented, so each channel has to have two openings – the inlet and an outlet – which take up additional space and can cause microchannel deformation at the outlet site.