Nicholas Kotov and the team of scientists from the University of Michigan has announced the pioneered methods of discrete mathematics previously used in finance, sociology, epidemiology and other areas to design bioinspired nanomaterials for reliable biomedical sensors and implants.
ANN ARBOR, Mich., May 21, 2021 /PRNewswire/ — From heart pace-makers to neuromodulation devices, bioelectric implantable devices are the future of biomedicine. Though the electronic design for implantation devices has advanced, the insulation coating has not received much attention. As a result, device failures arising from the degradation of the insulating material have become frequent. The insulating-coating has to provide flexibility, strong adhesion, biocompatibility, and resistance to cracks and delamination. Thus, creating the perfect insulating material is a long-standing challenge known to both engineers and clinicians.
Graph theory SIMPLIFIES THE design of CARTILAGE-INSPIRED Insulators for bioelectronics by The Kotov LAB
The team led by Prof. Nicholas A. Kotov took inspiration from the cartilage known for its unique mechanics, adhesion, and longevity. But the nanoscale structure of cartilage is very complex. Also, the coating of biomedical devices with collagen nanofibers – a biopolymer forming the stiff ‘skeleton’ of cartilage – failed to provide the required properties. So, the scientists had to start from scratch looking for a different polymeric material that can combine the properties of biological and abiological matter.
“One of the hardest parts of this work was to reveal the ‘hidden’ order governing the mechanical and other properties of seemingly disorganized networks of nanofibers forming cartilage.” says
Kotov.
The graph theory analysis enabled the short- and long-range organizational patterns characteristic of cartilage using graph theory indexes. It turned out that nanofiber network with nearly identical organization of nanofibers can be made from aramid nanofibers – the recently discovered cousins of ultrastrong Kevlar plastic. Pairing aramid nanofibers with special epoxy resins, led to a new family of coatings that combine high flexibility, crack resistance, and electrical insulation.
A comparison between different insulation materials revealed that these insulating coating have high longevity, excellent biocompatibility, and low inflammatory response – all the properties essential for bioelectronics. Also, the purposefully engineered aramid nanofiber coatings simplify device manufacturing of by taking advantage of energy-efficient self-assembly processes characteristic of all nanofibers. “Even though aramid coatings have great potential for biomimetic electronics” – Kotov cautions – “we have to be careful and extensive long-term testing of these materials is needed”.
The graph theory offers precision of structural design of nanofiber material that was previously missing. It essentially short-circuited the design of the materials that were previously done by costly and lengthy trial-and-error process. The materials engineering approach can also be universally applicable to many functional self-assembled materials.
