Researchers at McGill University’s Trottier Institute for Sustainability in Engineering and Design have developed a stretchable battery that uses gelatin combined with natural acids, such as citric or lactic acid, instead of toxic materials typically found in conventional cells, tells Tech Xplore.
Traditional batteries often rely on heavy metals and rigid casings, which make them unsuitable for flexible electronics and problematic for disposal. The new design replaces metal-heavy components with magnesium and molybdenum electrodes and uses a gelatin-based electrolyte enhanced by organic acid to boost ionic conductivity. This combination helps prevent the passivation layer that can form on magnesium electrodes, a layer that otherwise blocks reactions and degrades performance.
To enable stretchability, the team embedded the acid-gelatin electrolyte in a “kirigami” pattern. That design allows the battery to stretch up to 80% without losing performance, a critical trait for wearables and implantable devices.
In tests, the battery delivered stable voltage and capacity under deformation. As a demonstration, researchers used it to power a finger-mounted pressure sensor, showing that the battery could drive practical, flexible electronics, though its output (around 1.3 V) is slightly lower than a standard AA cell (1.5 V).
Beyond flexibility, the battery also offers biodegradability. Both the gelatin-based electrolyte and the magnesium electrodes degrade under suitable conditions, reducing long-term environmental impact compared with conventional batteries.
For engineers and designers working on wearables, medical implants, or distributed IoT devices, this represents a meaningful step toward sustainable, flexible power sources. If the performance is refined and the technology scaled, gelatin-acid batteries could help reduce e-waste while enabling new classes of soft, stretchable electronics.