China science

The power to heal: tiny generator could repair damaged brains, and give soldiers an edge

Team insert chip-based electric generator into mice and watch it dissolve without a trace once used; say same tech could be used to repair damaged neurons or give battle troops added intelligence

PUBLISHED : Wednesday, 16 March, 2016, 9:31am
UPDATED : Monday, 12 June, 2017, 12:53pm

Chinese scientists have developed a nano-sized electric generator that can disappear without a trace inside the human body over time, a breakthrough they claim will bring biodegradable implants on microchips closer to reality.

The technology, reported on the latest issue of Science Advances journal, will have a wide range of applications as it can generate electric pulses to repair damaged neurons and power “brain chip” implants for soldiers in the future, pundits said.

At present, most implants must be surgically removed at the end of their lifespan. To address this issue, a number of small electric devices made from biodegradable materials that can absorbed by the human body after use have been developed around the world.

But while biodegradable electronic implants have been a hot topic in medical and military research sectors for years, efforts to develop them remain handicapped by a number of technical issues.

The US-based Defense Advanced Research Project Agency (Darpa), for example, is now funding the development of biodegradable spy cameras and microchips that can be implanted in the body or brain of a solider, media reports show.

But the existing prototypes have all encountered the same key problem: they must be powered by external energy sources, which adds to the complexity and inconvenience of the system. DARPA’s soluble spy camera receives its charge from an external microwave source.

The new BD-TENG power generator from the Chinese team promises to solve this problem as it is made from layers of special, biodegradable polymers. Electricity is generated from the friction caused as they rub against one another.

By manipulating the physical properties of the polymers, the lifespan of the generator can be set precisely from a few hours to several years, said the team, which was led by professors Li Zhou and Wang Zhonglin at the Beijing Institute of Nano-energy and Nano-systems.

They managed to insert the device into a mouse and found that it had disappeared without a trace by a designated deadline.

“After nine weeks of implantation, the wound healed well, and no obvious infection was detected, revealing good biocompatibility of BD-TENGs,” Li and Wang reported in their paper.

“No significant inflammatory reaction was detected, as required for implantation of devices,” they added.

The team also used the generator to stimulate neuron cells and found its electric pulses could heal damaged neurons.

The BD-TENG can generate electricity from a number of biomechanical energy sources including the human heartbeat, the respiratory system or the changing pressure of blood vessels, depending on where exactly it is implanted, the team said.

But Professor Li Yuanqing, who studied human-machine interface at the South China University of Technology’s School of Automation Science and Engineering, expressed concern about using such technology on humans.

Even though military research organisations like Darpa claim to have been experimenting with brain chips for soldiers to combat post-traumatic stress disorder and other ailments, their real goal is to create super soldiers by boosting their mental or physical powers, Li said.

Li also warned that while the biodegrading technology would allow the chips to disappear after the soldiers have completed their service, the materials used could pose a risk to their health.

“I don’t think it is legal to use such chips on people in any country,” Li said.

The chips could also have technical limits, such as lower conductivity or a less stable performance compared to regular microchips, he said. Additionally, they may only affect a very specific area of the brain.

“I don’t think the technology we have for invasive implantation today is good enough - or even close - to facilitate their widespread application,” he said.