Move the slider to change the distance between tip and sample (input) and observe the resulting force (output). The interactive diagram is designed for use on a mobile device in landscape orientation.

Click on 1, 2 and 3 to select models with different indentation stiffness and to erase the force-distance trajectory.

The EPICAL hysteresis model describes phenomenologically and in unified form sequences of mechanical phenomena occurring in AFM-based nanoindentation experiments: Elasto-Plastic Indentation, Capillary Adhesion, and surface Leveling. The model is based on force-vs.-distance data measured with the atomic force microscope (AFM) during one large approach-retract cycle and it predicts the force (output) and the dissipated energy for arbitrary indentation trajectories (input). The model and the methodology for measuring the model parameters are described in our recent publication:

Rate-independent hysteretic energy dissipation in collagen fibrils
R. Magerle, P. Zech, M. Dehnert, A. Bendixen, A. Otto
Soft Matter 20, 2831–2839 (2024)