Biomaterial from University of Groningen uses protein‑like synthetic polymers to increase proton conductivity.

Benefits

  • Durable
  • Versatile
  • Increased conductivity

Applications

  • Bio‑electronics
  • Energy storage
  • Sensors

UN Sustainable Development Goals Addressed

  • Goal 9: Industry Innovation & Infrastructure

  • Goal 12: Responsible Production & Consumption

The Challenge

Synthetic polymers can be found in a variety of places, including clothing, furniture, and plastics. Although they are useful, it is challenging to accurately control their molecular structure. This structure controls many properties, including the ability to transport ions. If synthetic polymers used as biomaterials could be more accurately constructed, the ion transport could be optimized, and the material would perform better. Proton-conducting bio-polymers could be very useful for applications such as bio-electronics or sensors.

Innovation Details

The best way to precisely tune the proton conductivity of s is to tune the number of ionisable groups per polymer chain. To do this, the researchers first prepared a number of unstructured biopolymers that had different numbers of ionisable (carboxylic acid) groups. With the right nanostructure, charges will bundle together and increase the local concentration of these ionic groups, which dramatically boosts proton conductivity. It turns out that the nanostructure of spider silk is excellent for this task. The researchers engineered a protein-like polymer that has the main structure of spider silk but was modified to host strands of carbocyclic acid. The material was able to self-assemble at the nanoscale similarly to spider silk while creating dense clusters of charged groups, which are very beneficial for the proton conductivity. The measured proton conductivity was higher than any previously known biomaterials