Biomimetic membrane technology could impact multiple industries

The research, which could have significant applications in fields ranging from implantable artificial electric organs to water desalination, was led by scientists from the Adolphe Merkle Institute (AMI) at the University of Fribourg, together with international collaborators. EPFL's Laboratory for Bio- and Nano-Instrumentation (LBNI), led by Georg Fantner, lent their expertise and custom instruments for atomic force microscopy experiments required for the study, which has been published in the journal Nature.

According to an AMI press release, the new technique leverages the interface of an aqueous two-phase system to form and stabilize the energy-converting membranes membranes. By carefully controlling the conditions under which two immiscible water-based solutions interact with the opposing sides of the membranes, the researchers created membranes that are just 35 nanometers thick, but can cover areas larger than 10 square centimeters without defects. The method employs highly tunable block copolymers to form a bilayer at the interface of the two phases. The resulting membranes exhibit remarkable mechanical properties and self-healing capabilities, making them robust and durable for practical use.

These artificial membranes replicate the selective ion transport functions of natural cell membranes. By incorporating a natural transport peptide, the membranes achieve high ion selectivity, allowing them to generate electric power from solutions of different salts. This functionality is inspired by the electric organs of rays and other electric fish, which use similar principles to generate power.

This development could have significant applications in various fields. In energy storage, these membranes could enable the development of large-scale devices to store electrical energy. In water desalination, they may provide highly selective barriers that efficiently separate ions from water. In medical treatments such as dialysis, the membranes' ability to selectively filter ions could lead to more efficient and less invasive procedures. Finally, these membranes may enable implantable electric power sources that are recharged continuously from the body’s metabolic energy.

This research was led by AMI’s Biophysics group in collaboration with the Sustainable Functional Polymers group of Nico Bruns at the Technical University of Darmstadt, a Theory and Computer Simulation group at the University of Paris-Saclay, the Bio- and Nano-Instrumentation lab at EPFL, as well as the Polymer Chemistry and Soft Matter Physics groups at AMI.