Contact sensors have been used to gather information concerning contact or near-contact between two surfaces in medical applications, such as dentistry, podiatry, and in the development of prostheses, as well as in industrial applications, for instance to determine load and uniformity of pressure between mating surfaces, and in the development of bearings and gaskets. In general, these sensors include pressure-sensitive films designed to be placed between mating surfaces. These film sensors, while generally suitable for examining static contact characteristics between two generally flat surfaces, have presented many difficulties in other situations. For instance, when examining contact data between more complex surfaces, surfaces including complex curvatures, for instance, it can be difficult to conform the films to fit the surfaces without degrading the sensor's performance.
More serious problems exist with these materials as well. For instance, film-based contact sensor devices and methods introduce a foreign material having some thickness between the mating surfaces, which can change the contact characteristic of the junction and overestimate the contact areas between the two surfaces. Moreover, the ability to examine real time, dynamic contact characteristics is practically non-existent with these types of sensors.
A better understanding of the contact conditions at joints and junctions could lead to reduced wear in materials, better fit between mating surfaces, and longer life expectancy for machined parts. For example, one of the leading causes of failure in total joint replacement prostheses is due to loosening of the implant induced by wear debris particles worn from the polymeric bearing component. A better understanding of the contact conditions between the joint components would lead to reduced implant wear and longer implant life.
What is needed in the art are contact sensors that can provide more accurate and/or dynamic contact information concerning a junction formed between two surfaces of any surface shape.