Data-acquisition and instrument-control routines for the SMF group automated Johnson-Kendall-Roberts apparatus.

Adhesion between materials is commonly treated using the Johnson-Kendall-Roberts (JKR) theory[1]. JKR theory in the strict sense treats elastic solids, and therefore has no time-dependence. Real adhesives are often viscoelastic, and their properties vary with loading rate.

The classic JKR experiment involves manual measurement of contact force and area as two materials are driven together and pulled apart. This approach is laborious, and the loading rate during such an experiment is both uncontrolled and highly variable. This software consists of Matlab code to control a linear actuator, load cell and camera to make automatic force and area measurements at a controlled rate. These measurements allow the viscoelastic response of an adhesive to be measured. Results are published in ref. [2].

[1] https://doi.org/10.1098/rspa.1971.0141 [2] https://doi.org/10.1063/12.0001129