Real-time dynamically reconfigurable liquid metal based photolithography

We report real-time dynamically reconfigurable photomask by manipulating gallium-based liquid metal in microfluidic channel. As a demonstration of reconfigurable photomask, a polydimethylsiloxane (PDMS) based 7-segments microfluidic channel was designed and fabricated. With on-demand injection and withdrawal of gallium-based liquid metal in each segment channel, single digit numbers (`0´ to `9´) were dynamically reconfigured. For i-line and 400 nm wavelength UV lights, PDMS showed > 93% of light transmittance while PDMS + Galinstan^® showed <; 1 % of the light transmittance. In order to investigate achievable minimum feature size, various sizes of line shape, a horse shoe shape and Texas state map shape were demonstrated. The minimum feature size reliably and reproducibly created was 10 μm with the current approach.