Automated 3D assembly of hundreds of building blocks using optical tweezers

For many micro- and nano-photonic applications, current 3D prototyping approaches are unable to provide the necessary resolution or material integration. Optical tweezers (OT) are a potentially attractive solution due to their ability to manipulate various small objects with high precision. Here we show a custom-built automated OT 3D assembly platform that operates with manipulation speeds up to 0.22 mm/s and positioning accuracy better than 50 nm. Furthermore, to the best of our knowledge, we assemble the largest 3D structure to date using an OT platform, consisting of several hundred objects of multiple compositions.