MIT engineers have created the smallest ingestible temperature sensor, measuring just six by four millimeters. The device uses a circuit on a one-square-millimeter silicon chip that detects temperature within 0.01°C based on leakage current. Lead author Saransh Sharma, now at the University of Cambridge, explains the sensor uses backscattering to minimize energy consumption, allowing power requirements to be outsourced to an external antenna.

The system emits ultra-high-frequency radio waves that are modulated by an internal antenna and sent back to calculate temperature values continuously. Senior author Giovanni Traverso and MIT provost Anantha Chandrakasan envision applications including infection monitoring, anesthesia observation, pediatric fever tracking, and athletic performance monitoring. The technology could ultimately replace traditional thermometers for widespread use.