Soft electronic skin may soon become tougher, more repairable and far less wasteful, thanks to a new bio-based material developed by researchers at the National University of Singapore’s College of Design and Engineering. The material, known as an intrinsically dynamic biosubstrate, or IDBS, is designed to solve several persistent problems in wearable electronics at once: it can stretch repeatedly, repair damage, hold metal conductors in place and be remoulded or chemically broken down after use. The researchers say the technology could help make health-monitoring patches, robotic skin and virtual-reality interfaces more durable while improving the prospects for recycling discarded electronic devices.
Soft sensors translate physical changes—including movement, temperature, humidity and mechanical strain—into electrical signals. Their flexibility makes them comfortable and useful on the human body, but it also creates a major engineering weakness. Repeated bending, stretching and rubbing can cause thin metal conductors to detach from their polymer substrates. A cut or tear in the substrate can interrupt the electrical pathway entirely. Conventional materials such as petroleum-derived silicone and thermoplastic elastomers are difficult to recycle, meaning that even small, damaged sensors can contribute to the growing stream of electronic waste.
To create IDBS, the team led by Assistant Professor Zhai Wei combined two naturally occurring molecules: lipoic acid, a compound found in living cells, and phytic acid, which is abundant in plant seeds and grains. The synthesis relies on heat and does not require catalysts or organic solvents. The resulting material contains a molecular network held together by three interacting types of bonds. Dynamic disulfide bonds can break and reconnect, allowing the material to rebuild connections across a damaged region. More stable ester bonds provide structural reinforcement, while hydrogen bonds help dissipate mechanical energy and strengthen adhesion to metal surfaces.
This molecular architecture gives IDBS an unusual combination of flexibility and resilience. In testing, one formulation stretched to more than eight times its original length before breaking. When severely damaged at room temperature, the material recovered more than 80 percent of its original strength within six hours and more than 90 percent within 24 hours. Its repair performance remained above 90 percent after five repeated damage-and-recovery cycles. The process is not instantaneous, but it could allow a wearable device to recover from everyday cuts or tears instead of failing permanently after a single accident.
The researchers also focused on a less visible but equally important failure point: the interface between the soft substrate and its metal circuitry. A self-healing polymer cannot protect a sensor if its conductors peel away during use. The team tested IDBS with zinc circuits intended for electronic skin and silver films used as electrodes for recording heart and muscle activity. Heating the material to 85 degrees Celsius increased the mobility of its polymer chains, exposing chemical groups capable of interacting with the metal. When the material cooled, the network reorganised and created a much stronger bond.
For silver electrodes, heat-assisted deposition allowed metal particles to penetrate slightly beneath the surface of IDBS, anchoring the conductive layer within the polymer rather than leaving it attached only at the exterior. Peel tests showed that silver adhered three times more strongly to IDBS than to polydimethylsiloxane, or PDMS, a widely used silicone in flexible electronics. Adhesion was also one and a half times stronger than with styrene-ethylene-butylene-styrene, or SEBS, another common stretchable substrate. The stronger interface is crucial because it helps preserve electrical signals while the sensor bends, stretches and rubs against skin.
Prototype devices made with IDBS detected temperature, moisture from breathing and mechanical strain. Silver electrodes recorded heart and muscle signals comparable to those obtained with commercial electrodes. In a durability test involving 800 friction cycles against artificial skin, the IDBS electrodes continued to produce clear signals. On PDMS, by contrast, the silver layer detached and the recorded signals deteriorated. The result highlights a shift in design philosophy: the substrate is not simply a passive platform beneath the conductor, but an active component that can determine whether the entire sensor remains functional.
IDBS could also give electronic devices a second life after their first one ends. Reheating softens the material, allowing zinc circuits and other electronic components to be removed intact before the substrate is remoulded. A different recovery route uses ethanol to break down the molecular network. In that process, researchers can clean and recover the circuits, collect silver particles for use in conductive inks and reprocess the remaining material as an adhesive. After three remelting cycles, the biosubstrate retained more than 90 percent of its original stretchability.
A life-cycle assessment indicated that IDBS could have lower environmental impacts than PDMS, SEBS and polyurethane in several categories, including global warming potential and ecotoxicity. The most favourable results came from a circular-use model, although that assessment assumed a 95 percent recycling rate. The researchers now plan to extend the material beyond sensing layers to the chips and electronic components that process sensor signals. They also aim to improve its heat resistance so it can survive the manufacturing conditions used for flexible circuit boards. The findings were published in Nature Sustainability, suggesting that a material built from renewable chemical building blocks could help wearable electronics become not only smarter and tougher, but also easier to recover when their working lives are over.
Subject of Research: Soft, stretchable and recyclable substrates for durable wearable sensors and electronic skin
Article Title: A versatile sustainable biosubstrate stabilizing metal conductors for soft sensors
News Publication Date: 19 June 2026
Web References: Nature Sustainability article; NUS CDE researcher profile
References: DOI: 10.1038/s41893-026-01870-3
Image Credits: College of Design and Engineering, NUS
Keywords
Soft sensors, electronic skin, self-healing materials, recyclable electronics, sustainable materials, wearable technology, biosubstrate, flexible electronics, conductive metals, National University of Singapore
