Implantable circuits for the human body are close at hand
Researchers with The Ohio State University are currently developing an inexpensive silicon circuit that mimics human body chemistry. This electronic circuit will be able to operate and work in direct contact with live tissue inside the human body and essentially lead the way with creating devices that can cure or detect a disease in its early stage where it can be treated more easily.
According to Paul Berger who works as the professor of electrical and computer engineering and physics at Ohio State, the circuit, which is made of silicon, was coated with a protective layer and then placed into a fluid. After 24 hours in the fluid, which replicated the chemistry of the human body, there was absolutely no adverse affects to be found on the circuit.
Berger says that most silicon-based circuits never worked for them because of the different chemicals in the body that interfere with the electrical signals.
“Silicon is relatively cheap… it’s non-toxic,” Berger said. “The challenge is to bridge the gap between the affordable, silicon-based electronics we already know how to build, and the electrochemical systems of the human body.”
The story behind the creation of the circuit began when Berger inquired with the Bio-medical Engineering department about developing a way to detect special proteins that are created in the body when an organ is rejected after a recent transplant.
The sensor they experimented with was coated with a thin layer of aluminum oxide and done so to see if it would naturally block the positive and negative charges that are created from electrolytes in the body.
Both sodium and potassium, which are electrolytes, are naturally attracted to silicon where they are absorbed. This absorption of electrolytes would ruin a circuit’s ability to operate correctly so the team began testing whether electrolytes could be blocked from entering silicon with a layer of aluminum oxide. The aluminum oxide layer that was coated on the circuit was quite effective with preventing the silicon from absorbing anything the human body would naturally produce.
The research team claims that this is a big leap with developing long-term electrical sensors that can help doctors determine how much anti-rejection medicine a patient might need after an organ transplant.
Testing with coatings such as titanium are being looked at to see if they can get the sensor to work even more efficiently. In fact, Berger said that it is quite plausible that doctors may soon be able to replace damaged nerves with an artificial neuron and restore function as soon as it is implanted.
References: dx.doi.org/10.1049/el.2012.4283 - Ohio State University, ”The body electric: Researchers move closer to low-cost, implantable electronics.” June 10th, 2013. http://phys.org/news/2013-06-body-electric-closer-low-cost-implantable.html