On the way to biobased fuel cells

Publication in ScienceAdvances

According to the annual report of the German Pacemaker and Defibrillator Register, around 106,000 pacemaker operations took place in Germany in 2017 alone. Only about 77,000 of these were for actual implantation, and slightly more than 28,000 operations were for changing aggregates and systems or explantation.

Many of these additional operations are due to the limited life span of batteries of only five to ten years on average. This applies not only to pacemakers and defibrillators, but to almost all implants.

Especially for older patients, every invasive operation is associated with major health risks. This is why science has long been looking for an alternative to batteries. One possibility is the use of fuel cells, which do not have to be renewed, but which could previously only be manufactured from synthetic materials.

A German-Dutch research team has succeeded in creating decisive basic principles for the development of a fuel cell which, due to its bio-based production, leads to the least possible side effects and better compatibility with implants.

The scientists have succeeded in producing the heart of such a fuel cell from proteins - a membrane that enables electrochemical processes at both electrodes due to the good conductivity of protons.

To produce this membrane, the researchers used biotechnological processes that are usually used to optimise enzymes in detergents or to produce pharmaceutical proteins. Over several development cycles, a protein chain was created that contained a large number of negatively charged amino acids that were combined with sequences from spider silk.  The protein chains fold in such a way that the acid groups of the amino acids are responsible for the transport of the protons and the spider silk part for the mechanical properties. This design achieves proton conductivities that are much higher than those of any previously known biomaterials. This has laid the foundations for the future production of better implants that will enable communication between electronic components and the human body.  

The research results of Prof. Dr. Andreas Herrmann (DWI - Leibniz Institute for Interactive Materials) and Giuseppe Portale, PhD (University of Groningen) can be read in the issue of ScienceAdvances, which was published on July 17, 2020.