One-Step Acoustic Directed Assembly

Directed-assembly by applying external fields on materials can set them in a state of local equilibrium with complex spatial organization. Alas, electric, optical and magnetic fields usually require certain material characteristics (conductivity, transparency or magnetic susceptibility) that limit the span of possible applications. One of the advantages of acoustic techniques is that the only requirement for influencing a particle is a difference in compressibility and density between the particle and the surrounding medium (acoustic contrast), which is true for almost all dispersed systems.

We present a novel concept based on the idea that mechanical forces arising from standing surface acoustic waves can direct nanoparticles and products of ongoing chemical reactions to produce continuous and uniform micro-structures. A key feature of this approach is its modularity, as it could be implemented on various material systems. Due to the flexibility in material choice, this innovative approach will open the door to new ways to act upon materials, with envisioned applications for electronics, photonics and medical devices.