LAUSR

Sensor miniaturization enables applications such as minimally invasive medical procedures or patient monitoring by providing process feedback in situ. Ideally, miniature sensors should be wireless, inexpensive, and allow for remote detection over sufficient distance by an affordable detection system. We analyze the signal strength of wireless sensors theoretically and derive a simple design of high-signal resonant magneto-mechanical sensors featuring volumes below 1 cubic millimeter. As examples, we demonstrate real-time tracking of position and attitude of a flying bee, navigation of a biopsy needle, tracking of a free-flowing marker, and sensing of pressure and temperature, all in unshielded environments. The achieved sensor size, measurement accuracy, and workspace of ~25 centimeters show the potential for a low-cost wireless tracking and sensing platform for medical and nonmedical applications. Description Editor’s summary Minimally invasive medical procedures often require cameras or markers to track locations within the body. However, there are places that cables cannot reach, and there are challenges with imaging into deep tissues or trying to limit exposure to harmful radiation. Gleich et al. developed an innovative platform for magnetic tracking and sensing applications using magneto-mechanical resonators (MMRs). In theory and experiments, the authors showed that MMRs can outperform existing technologies such as radiofrequency markers in terms of sensitivity. They also demonstrate sensing applications (position and orientation, pressure, and temperature) and provide examples of spatial tracking in three dimensions. —Marc S. Lavine Low-frequency resonant magnetic wireless sensors smaller than 1 mm3 can be reliably detected up to 25 cm away.