Modeling thermal contact resistance at the finger-object interface.

Thermal contact resistance at the finger-object interface plays a significant role in our thermal perception and is an important parameter for the design of a myriad of electronics and thermal devices. Currently, its value is measured experimentally or, more commonly, is estimated using a semi-empirical model. This model was developed by Cooper, Mikic, and Yovanovich (CMY) in the 1960s for predicting contact resistance of metal-metal interfaces in a vacuum. In this work, it is shown that measured value of finger-object contact resistance is better predicted by a more recent correlation by Prasher and Matayabas (PM) that was developed by fitting contact resistance data for silicone gel-metal surface interfaces in microelectronic applications. Furthermore, it is show that the functional form of the empirical PM correlation can be derived using scale analysis of the finger-solid contact scenario, consequently can be considered a physics-based model. Comparing the two models against two previously published experimental data sets demonstrates that the PM model predicts well the thermal resistance between finger and variety of materials over a wide range of contact pressures. Specifically, for finger contact with significantly more conductive materials (thermal conductivity above 1 Wm