Researchers at Columbia University have engineered a revolutionary single-chip system, measuring less than 0.1 mm³, that can be injected into the body to accurately track temperature using ultrasound technology.
In 2019, OmniVision introduced a minuscule camera—0.575 mm long, 0.575 mm wide, and 0.232 mm high—that earned a Guinness World Record for its pinhead size, smaller than a grain of rice. The company highlighted its potential for minimally invasive medical procedures, including brain, ENT, and gynecological exams.
Published in Science Advances on May 7, 2021, Columbia University scientists unveiled the smallest injectable system integrated into a single square chip just 0.3 mm per side, with a volume under 0.1 mm³. Visible only under a microscope, it fits easily inside a hypodermic needle.
"This is a new 'system-on-a-chip' concept. This standalone chip forms a complete, functional electronic system," explained lead researcher Ken Shepard. "It could transform wireless, miniaturized implantable medical devices capable of sensing various parameters."
Designed specifically to monitor body temperature during ultrasound therapy, this compact system leverages its extreme miniaturization. Traditional tiny devices rely on radio frequencies for communication, but their wavelengths are too large for such a microscopic chip. Stacking components was also infeasible.
The team integrated a piezoelectric transducer for both ultrasonic power delivery and communication, paired with an ultra-low-power temperature sensor. Encased in a biocompatible parylene capsule, the device acts as a real-time temperature probe.
Extensive testing in mice at depths up to 2 cm yielded promising results, with theoretical capabilities reaching 5.7 cm. Ongoing research aims to expand functionality to measure additional biological parameters, such as via chemical or pH sensors.
