Theory, Measurement, and Application of Thermal Properties of Biomaterials

Biomaterials are capable of heat transfer-energy transport by virtue of a temperature gradient. In the case of a living biomaterial, the heat transfer capability of the material can be especially important because the state of life may depend upon the maintenance of a specific temperature. All of the three basic mechanisms of heat transfer, that is, conduction, convection, and radiation, can occur in physical situations involving biomaterials, but of these three, conduction is usually most important in detcrmining the heat transfer within the biomaterial itself. The ability of a biomaterial to transport energy by conduction is best characterized in the steady state by its thermal conductivity, k, and in the nonsteady state by its thermal diffusivity, rx. Because of the complex structure of most biomaterials, there is no adequate microscopic theory, such as that for solids and to a lesser extent for liquids, that allows the direct determination of k and rx of a biomaterial from some fundamental property or properties. For this reason, it is usually necessary to