Non-freezing cold injury (NFCI) of the feet has been identified as a major concern for the military and presents significant medical, operational and logistical problems. Therefore, a sensor sock for monitoring skin temperature has been developed. Miniture thermistors were incorporated within fibres to create an electronic temperature sensor yarn. A UV-curable resin was used to form micro-pods around the thermistors and to protect them from mechanical and chemical stresses during manufacture and use. The small size of the thermistors makes them virtually invisible to the naked eye. The effects of the resin micro-pods and the yarn fibres on the accuracy of the temperature measurements were examined using bespoke test apparatus. The results showed that the micro-pods and the yarn fibres have no significant impact on the temperature readings. Cyclical testing showed that the yarn is capable of handling mechanical strain. Finally, prototype temperature sensing socks were produced with five sensor yarns per sock, and tested for functionality. It is envisaged that the sensor sock will initially be used as a research tool. With further development the sock could be used to monitor long-term exposure to cold in the same way that radiologists monitor exposure to radiation.
This research received funding from the Defence Science and Technology Laboratory through the Centre for Defence Enterprise under contract number CDE 37926.
A video showing the developed temperature sensing sock is available below.
Details of this innovation and associated research are available in the following articles: