Published on March 31st, 2014 | by Cynthia Shahan0
Biodegradable, Implantable Battery Can Melt In Your Body
March 31st, 2014 by Cynthia Shahan
Modern medicine does not fall behind other business in this age of technology. Modern medicine focuses on integrating life-changing advances with progressive technological advances. A recent marriage of medicine and technology hopes to enable progress in monitoring and administering treatment with difficult health circumstances. This recent progress is a biodegradable, implantable battery that will help in the development of biomedical devices that monitor tissue or deliver treatments before being reabsorbed by the body after use.
“This is a really major advance,” says Jeffrey Borenstein, a biomedical engineer at Draper Laboratory, a non-profit research and development centre in Cambridge, Massachusetts. “Until recently, there has not been a lot of progress in this area.”
Mark Peplow of the journal Nature writes, “In 2012, materials scientist John Rogers at the University of Illinois at Urbana-Champaign unveiled a range of biodegradable silicon chips that could monitor temperature or mechanical strain, radio the results to external devices, and even heat up tissue to prevent infection.”
In a study published in 2012, ‘Biodegradable electronics here today, gone tomorrow,’ a team of researchers designed flexible electronic components that could dissolve inside the body and in water. The components could be used to make smart devices that disintegrate once they are no longer useful, helping to alleviate electronic waste and enabling the development of medical implants that don’t need to be surgically removed.
As the recent Nature article continues, “wireless power transfer might be problematic for devices that need to go deep within tissue or under bone. The components that receive the power are also quite complex.” And Borenstein notes, “anything you put in there is going to take up space.”
The innovative answer to this issue is found as Rogers and his collaborators have now created a fully biodegradable battery. In fact they have designed dissolvable devices:
Their devices, described last week in Advanced Materials, use anodes of magnesium foil and cathodes of iron, molybdenum or tungsten. All these metals will slowly dissolve in the body, and their ions are bio-compatible in low concentrations. The electrolyte between the two electrodes is a phosphate-buffered saline solution, and the whole system is packed up in a biodegradable polymer known as a polyanhydride.
Currents and voltages vary depending on the metal used in the cathode. A one-square-centimetre cell with a 50-micrometre-thick magnesium anode and an 8-micrometre-thick molybdenum cathode produces a steady 2.4 milliamps of current, for example. Once dissolved, the battery releases less than 9 milligrams of magnesium — roughly twice as much as a magnesium coronary artery stent that has been successfully tested in clinical trials, and a concentration that is unlikely to cause problems in the body, says Rogers. “Almost all of the key building blocks are now available” to produce self-powered, biodegradable implants, he says.
The long-term aims are really interesting. “Borenstein hopes that further research into both types of batteries could eventually yield implantable drug-delivery devices that are controlled by radio signals, or that dispense pharmaceuticals in response to a specific acute problem, such as an epileptic seizure.”
What is also notable, beyond the help for patients directly, Borenstein believes these devices will have environmental applications. For example, possibilities such as remediation efforts during an oil spill. Environmental officials might drop thousands of the tiny, wireless chemical sensors across an oil slick. They will simply dissolve in time back into the ocean.
For more on this news, check out the full Nature article.
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