A device for the measurement of the thermal properties of small (μL) volumes

A microfabricated sensor capable of measuring the thermal conductivity of small samples is presented. A micro heater and thin film thermocouples are formed on a polyimide substrate and subsequently used to thermally probe samples. Encapsulation of the devices by polyimide allows measurement of otherwise difficult to measure samples, such as conductive surfaces or wet environments. In combination with the lateral dimensions, it is anticipated that such devices will be of use for monitoring biological materials or other small scale samples. Mixtures of glycerin and water are used here to demonstrate the ability of the device to measure the thermal properties of small (~100μL) volumes.