UCLA

The purpose of this research is to increase the speed with which holographic optical tweezers (HOT) can individually assemble microscale particles for fabricating useful volumes of mechanical metamaterials in reasonable build times. HOT systems are unique among other additive manufacturing approaches in their ability to create true-3D structures with multiple materials, microscale features, and overhanging geometries. To scale up HOT-based fabrication, this research focuses on four primary goals: (1) scaling the number of particles that can be handled simultaneously using scanning holographic optical tweezers (SHOT), (2) developing efficient path planning and automation algorithms for efficiently delivering particles to their destinations within the fabricated structure, (3) modeling the dynamics of discretely-stepped optically-trapped particles to reliably handle them at high speeds, and (4) efficiently joining adjacent particles to produce a permanent structure. In addition, this work also demonstrates a proof-of-concept system that combines the HOT approach with the two-photon lithography approach, which allows for simultaneous fabrication and manipulation of microscale mechanisms in the same system for the first time. By improving the number and speed of particles that can be handled with the HOT approach, this work provides a promising path towards automated and scalable manufacturing of materials with extraordinary properties, such as microgranular lattices or microstructures with embedded strain energy.