Engineering news
University of Bristol researchers Paul May and Paul Nistor said the carbon material is one of “the major new biomaterials of the 21st century” after reviewing data and recent work with the substance.
Their paper, Diamond thin films: Giving biomedical applications a new shine, said the material is especially promising for implants because of three key properties: it is bioinert, causing minimal immune response; its electrical conductivity can be controlled with other substances; and patterns can be placed on it for cell growth.
The three properties mean diamond could “shape the way medical treatment will be performed, especially when invasive procedures are required,” the researchers claimed.
One application where the material could become “essential” is brain-computer interfaces, May told Professional Engineering. The devices could allow users to control new robotic limbs after paralysis, or alternatively computer signals could trigger muscle movements.
Some interfaces already exist, but diamond’s properties mean it could be used in permanent, long-life devices embedded in the brain, nervous system or spine, said May.
“You have one operation and it stays in there permanently, it embeds the sensor in there and that lives there longer than the lifetime of the patient. You don’t have to have any external systems at all. And if you get it right you could even access it like Bluetooth,” he added.
Some technology entrepreneurs are already investigating so-called “neural laces”. Tesla and SpaceX CEO Elon Musk’s Neuralink company aims to integrate artificial intelligence into human consciousness with interfaces, and company BrainGate is providing interface technology for clinical trials to help restore movements for disabled people.
As well as diamond’s impressive material qualities, which May claimed are better than slightly reactive alternatives such as titanium, he said they are also now so cheap they are “practically disposable”.
“People think about diamonds as expensive gemstones in Ratners or whatever, but nowadays with chemical vapour deposition (CVD) we can grow diamond in the lab for pennies, literally it’s just a few hours’ worth of electricity,” he said. “So diamond is now often cheaper than the cells you put on it.”
Diamond made with CVD, which involves exposing substrate wafers to energised methane and hydrogen, costs about $50 (£37) for a 1cm2 and 0.5mm thick plate.
Long-lasting diamond-tipped implants could also help control epilepsy and other conditions, said May, and the researchers highlighted CVD diamonds’ potential application in bone repair.
In high concentrations the material can be toxic, the researchers said, but they claimed the levels required for an adverse effect would be much higher than in biomedical uses.
The research was published in the Journal of the Royal Society Interface.