Transient Thermal Model for a Wearable Device in Contact with Human Skin

Makers of wearable devices, as in most areas of consumer electronics, try to provide as much performance and functionality in the use of these devices consistent with certain thermal limits. These thermal limits, of course, deal with peak temperatures in the silicon chips within the device. For wearables, the external temperatures of these devices are also critical from the viewpoint of user comfort and safety. To achieve the greatest accuracy in a thermal model for the wearable device, it is necessary to use a robust and accurate model for the transfer of heat into human skin. The typically used ad hoc assumption of an isothermal boundary condition representing the region of contact between a wearable device and human skin is no longer adequate.