A new force-clamp rheometry technique is used to investigate the mechanical properties of low-volume protein-based hydrogel samples tethered between a voice-coil motor and a force sensor. An analog proportional-integral-derivative (PID) system allows for the 'clamping' of the force experienced to the desired protocol.
Khoury, L. R., Nowitzke, J., Dahal, N., Shmilovich, K., Eis, A., Popa, I. Force-Clamp Rheometry for Characterizing Protein-based Hydrogels. J. Vis. Exp. (138), e58280, doi:10.3791/58280 (2018).