Directed Assembly of Nanoparticles Using Standing Surface Acoustic Waves

In our lab, we develop different methods which direct materials to form patterns and micro-structures. This project deals with standing surface acoustic waves (SSAWs). We want to study how these waves affect the formation of structures from suspended nanoparticle solutions. Under the exposure of SSAWs, nanoparticles in a microfluidic channel would be forced towards pressure nodes (for particles with a positive acoustic contrast factor in the medium) forming new microstructures. While previous work of SSAWs focused on ordering, sorting and separation of particles, the novelty of our work is that we use them to form new materials. We use suspended silver nanoparticles that can be sintered at room temperature with exposure to chloride ions. Streaming the silver suspended nanoparticles with chloride ions solution under the SSAWs field could sinter the particles in a micro-fiber shape.