Modern rapid fabrication technologies based on additive layering are inherently slow. We asked ourselves if it is not possible to instantly form an entire object in “one shot”. The idea is to use ultrasound to assemble particles and cells into the shape of the object. This led to the development of the acoustic hologram technology with which we are able to generate very high-fidelity acoustic fields. We are now working on realizing the vision of this matrix-free molding technology.
This research project revolves around optimizing the way we can use acoustic radiation forces to manipulate particles and also assemble particles into complex shapes. We have just demonstrated a first proof-of-principle experiment for 2D assembly (see image), and we also work on chemical pathways to fix acoustically-formed particle assemblies. We are also manipulating biological cells with our newly formed acoustic hologram fields.
We aim to move from 2D to 3D shapes, which will require highly sophisticated tools to compute the proper fields as well as new experimental setups.
A related major area of research in the group is local sonochemistry using high-power transducers and acoustic holograms. By creating high sound pressure spots (> 1 MPa) in spatially limited regions we can initiate chemical reactions via heat or cavitation.
Melde, K., Choi, E., Wu, Z., Palagi, S., Qiu, T., & Fischer, P. (2018). Acoustic Fabrication via the Assembly and Fusion of Particles. Advanced Materials, 30(3). doi:10.1002/adma.201704507