Reducing, refining and replacing animal models (3R principle) requires new technologies to create tissue models in vitro, which physiologically resemble organ-specific tissues at the same level (or better). Much work has been devoted to conventional biofabrication techniques, such as 3D-printing. Bioassembly methods could add another approach to the bioengineer’s toolbox by gently manipulating and stimulating cells at a distance. Ultrasound is especially promising due to its limited side effects, high transmission through tissue and low required intensities. Latest achievements in the scientific community are not readily translated to be used in a regular biolab. The aim of this project is to develop a fully operational, stand-alone benchtop bioassembler that uses ultrasound and holography to instantly aggregate biological cells, spheroids, particles or hydrogel capsules into defined 3D structures. The goal is that the device can be operated in biolaboratory environments and under typical process conditions, e. g. it can withstand sterilization using ethanol and ultraviolet light and operate at 37°C. Another planned feature is that the user interface is semi-automatic, designed to minimize user interaction and to help enforce a reproducible protocol for 3D cell culture using bioassembly. New algorithms have to be developed to compute optimal holographic plates for user-defined assemblies. Overall, the project will lead to a fast, programmable assembler where cells in suspension can be assembled with ultrasound into compact shapes directly from suspension – thereby maximizing cell density and minimizing any stress on cells.
