A new biosensor implantable in the human body and functioning without the aid of a battery has been developed by a research team at the National University of Singapore (NUS). This small sensor could make what is still considered a dream come true, i.e. to be able to measure, for example, a patient’s blood sugar, heart rate or other physiological conditions fully automatically, wirelessly and without the hassle of having to refer to a battery.
The battery itself remains one of the greatest technological limitations for sensors of this type. Very often they are too small and therefore the battery must be implanted close to the sensor or must be held externally and connected by wire, all of which limit the patient’s sense of comfort and autonomy. Precisely for this reason, sensors have been developed with a built-in reader to detect chemical or pressure changes through magnetic fields, all without battery. The sensor itself, however, must be large enough to emit this signal.
Because of all these features, until now researchers have never been able to create micro-sensors for the human body smaller than a millimeter. Instead, the Singapore research team, led by Professor John Ho, has developed a new way to measure the signal through the calibration of the wireless reader. The reader chip is much more sensitive than those present in current body sensors, so much so that it can read very small signals emitted by submillimetric microsensors.
The new sensor, which measures 0.9 mm in diameter, can be implanted under the skin using a syringe and, during the experiments carried out in the laboratory by the researchers, has already been able to monitor breathing and heart rate. The results of this project were then published in a study that appeared in Nature Electronics.
“We hope that our breakthrough is pioneering the future of minimally invasive health monitoring solutions in which patients are immediately alerted whenever their physiological conditions such as heart rate and blood sugar exceed a critical threshold,” Professor Ho reports in a press release on the NUS website.