Towards Computing with Water Droplets

H. Mertaniemi, R. Forchheimer, O. Ikkala, R.H.A. Ras
Aalto University, FI

Keywords: superhydrophobic surfaces, droplet-droplet collisions, Boolean logic

Summary:

Encoding and manipulation of information in fluid states may not compete with electronic and optical data processing, but provides an orthogonal concept for programmed fluid and reactant handling and could even allow simple devices that are less vulnerable for electric disturbances. We present a new approach for fluidic logic gates, based on the newly discovered non-coalescing rebounding collisions between water droplets moving on a superhydrophobic surface. They allow Boolean logic operations, such as the AND/OR and NOT/FANOUT gate, and the flip-flop memory, as elements for fluidic computing. We also demonstrate conditions for droplet coalescence to provide programmed chemical reactions of confined reactants. The work provides a new paradigm for computing using fluids and programmed lab-on-a-chip applications using chemical and biochemical cargo.