Two-photon polymerization of anisotropic composites using acoustic streaming

In this work, an acoustic streaming-assisted Two-Photon Polymerization process (TPP) was developed for manufacturing anisotropic particle-polymer composites. Acoustic field (AF)-assisted constant microcirculation of nanoparticles within a droplet, also known as acoustic streaming (AS), results in nanoparticle trapping within TPP printed grooved surfaces. The effect of the acoustic voltage on the flow velocity and particle trapping efficiency is modeled and characterized. The identified optimum input voltage was used to generate the proper acoustic streaming to trap particles within polymer grooves during TPP process to produce a three-dimensional (3D) anisotropic particle-polymer composite in a layer-by-layer fashion. Experimental results validated the feasibility of the proposed manufacturing approach.