http://www.digitaljournal.com/science/sonic-microchips-could-monitor-the-body-s-health/article/409733

Sonic microchips could monitor the body’s health

Posted Oct 20, 2014 by Tim Sandle
Scientists have an idea that involves planting tiny electronic devices deep inside the body in order to monitor health and deliver selective therapies to treat specific illnesses.
A computer generated image of a soundwave.
A computer generated image of a soundwave.
Lifesun
This may sound like science fiction, however for some scientists the concept is a reachable reality. The main problem is not the technology itself, but in making devices small enough to fit inside the body and for these implants to have sufficient power.
To overcome this, scientists based at Stanford are working on a method to send power wirelessly to "smart chips" that can be implanted in the body. Such chips can be programmed to perform medical tasks and to send back the results to a computer. The method that the scientists are working on involves beaming ultrasound at nano-tech device implanted inside the body (the device overall is less than a millimeter). The current prototype is the size of the head of a ballpoint pen.
The technique of powering a device through ultrasound is called piezoelectricity. Here electricity is generated through compression changes. As the device undergoes tiny changes as a result of pressure, as it returns back to shape, this process (decompression) — a little like compressing a spring — generates electricity which powers the device. This compression-decompression process happens at a rate of one million times per second.
The device is designed to convert the incoming sound waves into electricity. The device can also process commands in related to medical information and to send data back to a computer. A working prototype of the wireless medical implant system was presented to the IEEE Custom Integrated Circuits Conference in San Jose.
A related tranche of research, from the same research team, is to develop a sound-powered implant for studying the nervous system to treating the symptoms of Parkinson's disease. It is thought that such tiny nodes have the potential for addressing neurological disorders.
If the model is successful, researchers aim to test many other applications using the technology to wirelessly power small implants deep inside the human body.