MIT engineers have developed a novel ingestible temperature sensor that addresses the limitations of existing oral and forehead thermometers, as well as the size constraints of current ingestible sensors. The new device, measuring just six by four millimeters, is capable of sending continuous temperature updates with high precision, detecting temperature changes within 0.01 °C. This is achieved through a one-square-millimeter silicon chip circuit that utilizes an oscillator based on leakage current, whose frequency varies with the surrounding temperature.
The sensor’s energy efficiency is enhanced by a backscattering technique, which allows most of the power requirements to be met by an external antenna. The device emits an ultra-high-frequency radio wave, modulated by an internal antenna and received by the external antenna, enabling temperature calculation. Lead author Saransh Sharma describes it as “the smallest ingestible capsule that we have seen for temperature-sensing paradigms.” The researchers envision applications ranging from monitoring infections and post-anesthesia patients to tracking fevers in children and aiding ovulation detection, with potential use for athletes, soldiers, and individuals exposed to extreme temperatures. Co-author Giovanni Traverso highlights the sensor’s potential to enable early infection identification, particularly beneficial for immunosuppressed populations, with the long-term goal of replacing conventional thermometers. Source