A recent US study revealed the creation of a system on a single chip covering an area of less than 0.1 mm³. According to the researchers, the device powered by ultrasound can be injected into the human body to measure its temperature.
The smallest injectable system contained in a chip
In 2019, the US company Omnivision unveiled a tiny camera whose dimensions are listed in the Guinness Book of Records. With its 0.575mm in length, 0.575mm in width and 0.232mm in height, this camera is smaller than a grain of rice. According to the creators, the device could be suitable for many medical examinations (brain, ENT, gynecology, etc.).
In a publication in the journal Scientific progress on May 7, 2021, researchers from Columbia University in New York (United States) presented the smallest injectable system integrated in a single chip! Square in shape, the chip measures only 0.3 millimeters on a side, or a volume of less than 0.1 mm³. Its size is such that it can fit inside a hypodermic needle, and of course, can only be subjected to a observation under a microscope.
“This is a new idea of a ‘system chip’. This chip which alone, without anything else, is a complete functional electronic system. This should be revolutionary for the development of miniaturized wireless implantable medical devices capable of detecting different things ”, said Ken Shepard, principal author of the work in a statement.
A very specific use
The researchers explain that this simple system is intended to measure body temperature during ultrasound therapy. It is a question of a very specific use which naturally results from the miniaturization of the device itself. In addition, it should be noted that a significant number of small devices use radio frequencies in order to communicate. Nevertheless, the wavelength concerning these devices remains too big for this chip microscopic.
In addition, it is completely impossible to integrate a battery. Scientists then opted for the use of a piezoelectric transducer. The latter allows communications as well as ultrasound power. The device is also coupled with a low consumption temperature sensor. The system therefore embodies a kind of probe allowing the measurement of body temperature in real time.
The device in a parylene capsule – ensuring biocompatibility – has undergone a series of tests with encouraging results. The researchers implanted it in mice at a depth of 2 cm and say it is theoretically possible to go up to 5.7 cm. In addition, research is continuing in order to give the system the possibility of measure other biological parameters using chemical or pH sensors.