Vision-Based Contact Adhesion Measurement Method on Soft Matter Surfaces

Adhesion property measurements contribute to a comprehensiveunderstandingof the mechanical properties of soft matters. Indentation tests area common method for measuring the adhesion force. However, indentersgenerally have a large volume and a small sensing angle and, thus,are not conducive to local detection in high-precision environments.Here, we propose a vision-based contact adhesion measurement (VisCAM)method to achieve the contact image and adhesion force on soft mattersurfaces from the perspective of indentation direction. The couplingof the 7.6 mm diameter probe and a flexible fiber makes the systemsimilar to a miniaturized endoscope. Classical contact theories andfinite element models are used for the contact mechanics analysisof silicone rubber. The image grayscale-load mathematical modelis constructed based on the change in contact light spot. Finally,the uncertainty of the system is less than 4%, and the measurementerror is 0.04 N. In-vitro kidney indentation experiments showed thatthe local adhesion force measurement of soft tissues can be completed.Our method provides better solutions for understanding the adhesionproperties of soft matters.