This breakthrough technology was recently featured in the journal Science.
The University of Arizona member of the research team is Dr. Marvin J. Slepian, practicing cardiologist and professor of medicine in the Sarver Heart Center. He also has a joint appointment in the UA biomedical engineering department.
Water Soluble Circuits
Slepian said biodegradable electronics evolved from previous research on stretchable electronic circuits that could be placed on balloon catheters for cardiovascular treatments. Then the researchers decided to take that technology a step further and make it altogether biodegradable. They developed a toolbox of totally biodegradable components made of silicon, magnesium and silk that dissolve in minute amounts of water or other fluids.
Silicon is the industry standard for integrated circuits. It is the semiconductor material. Silicon normally does not dissolve well in water or biofluids – yet when hammered into ultra-thin flexible sheets, it will completely dissolve. The end product is silicic acid, a well-known nutritional supplement.
Magnesium is the conductor. Magnesium is water soluble – and a common ingredient in multivitamin tablets.
Silk is used to encapsulate the circuits. It also is water soluble – but the dissolution rate can be controlled – so the electronics package could potentially be immersed in water or biofluids for a year or more without completely dissolving.
The Start of a Medical Revolution
Biodegradable electronics could not only revolutionize medicine – but also environmental monitoring and consumer electronics. Transient electronics could sense and measure key parameters of a chemical spill, transmit data, then ultimately degrade, leaving no ecological impact. Antiquated smart phones and other portable devises could potentially be dissolved, rather than ending up in the landfill.
But Slepian is most excited about the medical applications. He collaborates with researchers at the University of Illinois, Tufts University and Northwestern University.
In laboratory studies they’ve already successfully used transient electronics to monitor and prevent bacterial infection in surgical incisions. Surgical infections are a leading cause of re-admission to hospitals.
Other applications could include delivering regulated dosages of drugs, monitoring kidney or lung function, even catheters that dissolve. Green biomedical technologies ultimately could significantly reduce medical waste.
“We are thinking about marrying this technology with existing devices – for example the total artificial heart,” Slepian said. “Ideally we’d like to be able to implant transient electronic sensors along with the devise to keep track of the blood pressure in the pulmonary artery or the aorta for the first two weeks after surgery. This would help immensely with the management of such patients.”
In addition to his UA positions, Slepian is co-founder and chief scientific officer of SynCardia Systems, the Tucson manufacturer of the first and only FDA-approved total artificial heart. He has a long history of research and development with biodegradable biomaterials. In the late 1980s, he introduced the prototype for the first form of biodegradable stenting.
But that’s what you’d expect from the kid who built a heart-lung machine for his seventh-grade science project. He still has it in his library.
“I’ve had a long background in entrepreneurship and I’ve started a lot of companies – more than a dozen,” Slepian said. At the Eller College of Management, “I teach a class on Innovation Translation and Medical Entrepreneurship based on the 25 years of experience that I have in doing this and seeing how you can convert an idea into reality.”