Molecular switch turns peptides into power-generating biomaterials

A collaborative team of Indian researchers has uncovered a simple molecular strategy to transform peptides — the natural building blocks of proteins — into highly efficient piezoelectric materials. These biomaterials can convert mechanical forces such as heartbeat, breathing, or walking into electrical energy, opening the door for implantable medical devices that power themselves.

Piezoelectric materials generate electricity when pressed, bent, or stretched. They are already used in pressure sensors, ultrasound devices, and energy-harvesting systems. However, conventional piezoelectric materials are mostly ceramics — brittle, environmentally taxing, and often unsuitable for use inside the human body. Scientists have long sought softer, safer, and biocompatible alternatives.

The research team, led by Dr Goutam Ghosh at the Centre for Nano and Soft Matter Sciences (CeNS), Bengaluru, in collaboration with IISER Kolkata and JNCASR, focused on peptides. While peptides are safe, biodegradable, and tissue-compatible, achieving strong piezoelectric performance from them had remained a challenge.

Using advanced imaging techniques such as atomic force microscopy and field emission scanning electron microscopy, the team found that peptide molecules form nanofibers in water with no piezoelectric response. But when just one percent of a suitable co-solvent was introduced, the molecules reorganised into a highly ordered supramolecular arrangement. This instantly switched on a strong piezoelectric response — without altering the peptide's chemical composition.

The transformation works because controlled chiral self-assembly aligns molecular dipoles into a non-centrosymmetric structure, a fundamental requirement for piezoelectricity. The engineered peptide nanomaterials achieved a piezoelectric coefficient of nearly 30 pm V⁻¹, a notable performance for a peptide-based material.

The findings, published in Angewandte Chemie International Edition, offer a blueprint for designing sustainable functional biomaterials without chemically modifying the molecules. Such materials could one day power wearable electronics, implantable medical sensors, electronic skin, and biosensors by harvesting energy from natural body movements. Beyond healthcare, they present an environmentally friendly alternative to conventional piezoelectric materials for sustainable soft electronics.

The work highlights India's growing strength in supramolecular chemistry, combining molecular design, advanced nanoscale characterisation, and computational simulations to address complex scientific problems.