Fig. 5.

Programmable single-droplet transport via digital acoustofluidics. The hydrodynamic traps are activated following a pre-programmed movement sequence, resulting in the digital hydroacoustic formation of the letters ‘DUKE’. Each pixel consists of four independent IDTs; therefore, each droplet can be transported dynamically in any direction on the x–y-plane using a trap-and-release mechanism using an off-chip electromechanical relay controller. Scale bar: 8 mm