The Contact Adhesion of Self-Adhesive Strain Gauges

Thin pieces of flexible polymers may be adhered to rigid substrates merely by pressing the two surfaces into intimate contact. The peel strength of the bond is poor, but the shear strength can be sufficiently high for strain gauge operation. This paper offers an explanation for the adhesion which can account quantitatively for the behaviour of various materials. Frictional phenomena, resulting from a normal force produced by the surface tension of a surface film, can explain why a gauge with a PVC body does not slip. With other polymers, other liquids or electrostatic effects may be of importance. Any surface “fluid” film of sufficiently high viscosity that viscous effects are important will behave as an integral part of the elastomer.