3D mechanical characterization of single cells and small organisms using acoustic manipulation and force microscopy

It is currently challenging to mechanically assess 3D specimens without manual handling. Here the authors combine a micro-force sensor and an acoustically controlled manipulation device to enable rotation of samples while assessing mechanical properties at the chosen region. Quantitative micromechanical characterization of single cells and multicellular tissues or organisms is of fundamental importance to the study of cellular growth, morphogenesis, and cell-cell interactions. However, due to limited manipulation capabilities at the microscale, systems used for mechanical characterizations struggle to provide complete three-dimensional coverage of individual specimens. Here, we combine an acoustically driven manipulation device with a micro-force sensor to freely rotate biological samples and quantify mechanical properties at multiple regions of interest within a specimen. The versatility of this tool is demonstrated through the analysis of single Lilium longiflorum pollen grains, in combination with numerical simulations, and individual Caenorhabditis elegans nematodes. It reveals local variations in apparent stiffness for single specimens, providing previously inaccessible information and datasets on mechanical properties that serve as the basis for biophysical modelling and allow deeper insights into the biomechanics of these living systems.

Automated summary

The authors combined a micro-force sensor with an acoustically controlled manipulation device to rotate biological samples and quantify mechanical properties at multiple regions of interest within a specimen. The versatility of this tool was demonstrated through the analysis of single Lilium longiflorum pollen grains and Caenorhabditis elegans nematodes, revealing local variations in apparent stiffness and providing previously inaccessible information on mechanical properties for biophysical modeling.