Abstract 

Biofabrication includes methods that print bioinks or directly assemble biological components (e. g. cells or scaffold materials) with the goal of creating functional tissues. Most of these methods require direct mechanical access (e. g. extrusion printing or aspiration-based pick & place) and work serially (point-by-point or layer-by-layer), which scales poorly to volumetric shapes and applies undue stress on living cells. Over the last decade, ultrasound emerged as a tool for contactless manipulation of matter, including microparticles and biological cells. Its ease-of-use and favorable operating parameters led to a wide adoption especially in the microfluidics community (e. g. for cell sorting). However, the effects of ultrasound can act over much larger length scales, provided that there is sufficient control over the sound field. In this talk, I will present how ultrasound combined with holographic beamforming enables us to create very complex sound fields, which can direct the parallel assembly of matter to arbitrary shapes in 3D. As such, ultrasound promises to become a new tool for biofabrication, enabling the formation of cell aggregates without contact. 

BioSketch

Kai Melde leads a CZS junior research group at the Institute for Molecular Systems Engineering and Advanced Materials (IMSEAM), Heidelberg University. He is interested in acoustic holography and its use for particle manipulation and liquid handling within the context of biofabrication. He studied mechatronics at the Technical University of Dresden, and after receiving his M.Sc. in 2009 worked as a technical staff at the Palo Alto Research Center (California, USA). In 2013 he returned to Germany and joined the Max Planck Institute for Intelligent Systems in Stuttgart as a research assistant and in 2019 received his Ph.D. in conjunction with the Karlsruhe Institute of Technology. After a postdoc at the Max Planck Institute for Medical Research, in 2023 he received a Nexus grant from the Carl Zeiss Foundation to start his own research group in Heidelberg.