Scientists at UC San Diego School of Engineering have recently detailed a "near-zero-power" temperature sensor running on 113 picowatts, meaning that almost ten billion of such devices could be powered by a single watt. A related study authored by one Hui Wang that was published by Nature describes the creation as being able to work for years with just a small battery, thus making it potentially revolutionary in terms of Internet of Things (IoT) devices and wearables in particular. The solution was made possible through "gate leakage," a phenomenon that's usually seen as a problem in the industry, entailing electrons that leak through transistor gates that are becoming increasingly thinner as transistors get smaller. Instead of trying to eliminate that leakage, UC San Diego's engineers and scientists opted to try and control it instead, essentially creating a temperature sensor that's exclusively powered by energy that would otherwise be wasted. The device itself also detects temperature and converts it to digital measurements in a radically different manner to that of its alternatives, with the sensor being capable of doing so in a manner that's 628 times more efficient than contemporary methods.
The current prototype isn't without its faults and is primarily lacking in terms of speed; while much less energy-efficient, contemporary alternatives are also faster to present users with accurate readouts and some may even have a wider range of supported temperatures. The aforementioned solution can make readings between -4 and 104 degrees Fahrenheit, i.e. -20 and 40 degrees Celsius, and coupled with the fact that it isn't as quick as similar solutions, its applications cannot extend to critical systems and are generally limited to consumer electronics. The creators of the device said that in the context of wearables, the sensor's speed isn't a massive issue given how the temperature of a human body doesn't change in a rapid fashion, though they admitted that the device can still be improved and made more accurate.
The wearable industry as a whole has been somewhat stagnating in recent years, with fitness bands being the only product category that found a larger audience. An update on this segment and related technological advancements should follow in the coming months.