Diamond-studded electrode: a cure to paralysis

A diamond is forever, not only on your ring, but also inside your body-- implants made from these shiny stones can cure paralysis. Two Case Western Reserve University researchers are building implants made of diamond and flexible polymer that are designed to identify chemical and electrical changes in the brain of patients suffering from neural disease, or to stimulate nerves and restore movement in the paralyzed.

The work of Heidi Martin, a professor of chemical engineering, and Christian Zorman, a professor of electrical engineering and computer science, is years from human trials but their early success has drawn interest worldwide. 

Unlike standard electrodes, diamonds don't corrode. Diamond is so hard and rigid, however, that an entire implant made of the stuff would quickly damage surrounding tissue and the body would seal off the implant as if it were a splinter. The key is to use just enough diamond i. e. just the amount of diamond at the biological interface - where the device connects with a nerve

The real diamond is grown as a film - under high temperature, in a vacuum. By adding impurities  properties of diamond is changed. For electrodes, boron is added, turning the diamond blue. Blue diamonds, including the famous Hope Diamond at the Smithsonian, conduct electricity. Because diamond is made at 800 to 900 degrees celsius, a temperature that would melt the polymer base. Diamond is first selectively grown  in a series of tiny squares of diamond film on silicon dioxide, the stuff of sand and quartz.

Then it is laid in a thin flexible polymer that fills in the gaps between diamonds, followed by a layer of metal that connects to the back of the diamonds and will conduct electricity.
Lastly, he adds a thick layer of flexible polymer base. Then device is dropped in hydrofluoric acid, which eats away the silicon dioxide and frees the probe. 


Small, cortical probes that measure chemical changes at a location in the brain or along a nerve have two diamond contacts affixed. These probes are designed to assist health researchers who are trying to understand the role of chemicals in stimulating nerves or communicating within the brain. Recent research has found, for example, a link between a deficiency in the neurotransmitter dopamine and Parkinson's disease. Lab tests have shown one diamond-coated electrode can monitor chemical and electrical signals as well as stimulate nerves.