Finding out what鈥檚 going on in an injured brain can involve several rounds of surgery, exposed wounds and a mess of wires. Perhaps not for much longer. A device the size of a grain of rice can monitor the brain鈥檚 temperature and pressure before dissolving without a trace.
鈥淭his fully degradable sensor is definitely an impressive feat of engineering,鈥� says , a biomaterials scientist at the University of Sheffield, UK.
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The device is the latest creation from lab at the University of Illinois at Urbana-Champaign. They came up with the idea of a miniature dissolvable brain monitor after speaking to neurosurgeons about the difficulties of monitoring brain temperature and pressure in people with traumatic injuries.
Unwieldy wires
These vital signs are currently measured via an implanted sensor connected to an external monitor. 鈥淚t works, but the wires coming out of the head limit physical movement and provide a nidus for infection. You can cause additional damage when you pull them out,鈥� says Rogers. It would be better to use a wireless device that doesn鈥檛 need to be extracted, he says.
So Rogers鈥檚 team developed an electronic monitor about a tenth of a millimetre wide and a millimetre long made of silicon and a polymer. These materials, used in tiny amounts, are eventually broken down by the body, and don鈥檛 trigger any harmful effects, says Rogers. 鈥淭he materials individually are safe. The total amount is very small. It鈥檚 about 1000 times less than what you鈥檇 have in a vitamin tablet.鈥�
The sensor can measure subtle fluctuations in electrical resistance that result from changes in the pressure and temperature of the brain. Measurements are then wirelessly transmitted to an external device using radio waves.
When Rogers鈥檚 team tested the sensors in rats, they found that they were as accurate as existing monitoring devices. The tiny implants transmitted information for about a week until they stopped working. After three months, the implants had disappeared.
A decade away?
Rogers thinks that similar devices could be used to monitor other aspects of brain health, as well as other body organs.
鈥淭his work could potentially address an unmet clinical need,鈥� says at Carnegie Mellon University in Pittsburgh, Pennsylvania. 鈥淚f manufacturing and regulatory challenges are appropriately addressed, this device could enter the clinic within 5 to 10 years.鈥�
Rogers鈥檚 team have previously created bendy implants that can cover a rabbit鈥檚 heart and keep it beating, or use the movement to generate electricity to power other implants. The group have also developed stretchy electronic 鈥渢attoos鈥� .
Journal reference: Nature, DOI:
(Images: J. Rogers, University of Illinois)
