New Soft Optical Sensor Advances Heart and Brain Activity Mapping

Continuous monitoring of cardiac and neurological activity is crucial for diagnosis and therapy, yet current electrode-based implants can damage soft tissue and degrade signal quality. Rigid materials and extensive wiring create mechanical mismatch and electrical noise, limiting long-term use. Clinicians also face challenges when sensors heat surrounding tissue or fail under repeated bending. To help address this challenge, researchers have now developed a soft optical sensor designed to map organ electrophysiology with greater stability and lower interference.

The fully flexible “optrode” was created at the University of New South Wales (UNSW) School of Biomedical Engineering. It converts the body’s electrical activity directly into light, enabling optical readout without local electronics at the tissue interface. The design aims to mimic the softness of human tissue to support safer, longer-term implantation.

The device replaces brittle components with soft, high‑performance polymers that interact safely with the body. A specialized conductive polymer remains functional after 10,000 bending cycles, supporting durability in moving organs. A central layer of highly sensitive liquid crystals detects submillivolt amplitudes and aligns according to signal strength, producing quantifiable optical outputs.

Because the optrode operates optically at the recording site, it does not require bulky amplifiers or metal leads near tissue. This architecture reduces susceptibility to electrical interference that commonly contaminates bioelectronic recordings. The sensor can be miniaturized to tens of microns—about half the width of a human hair—without loss of signal quality or added electrical noise.

Biocompatibility findings include a 98.4% viability rate and in vitro tests showing no toxicity or contamination compared with silicon controls. The technology has been validated in animal testing, and additional in vivo studies are planned to improve signal resolution. Findings were published in npj Flexible Electronics on July 30, 2026.

Commercial development is progressing through Sevren Pty Ltd, established to accelerate translation of the platform. Beyond cardiac and brain mapping, the approach could be adapted to monitor the gut, muscles, or individual cells. Planned enhancements include broader bandwidth to capture faster electrophysiological events and refined liquid‑crystal alignment to elevate sensitivity.

“Bioelectronic implants are devices that can be placed in the body to monitor electrical signals from organs like the heart and brain. They help doctors track changes and patterns in a person's health over the short and long term. They're usually made of rigid materials like silicon and metal, and because our internal organs are soft and constantly moving, this mechanical mismatch often leads to tissue damage, scarring and even the body 'rejecting' the implant. They also rely on metal wires that can break when bent or pick up a lot of electrical 'noise' from the environment, compromising data quality. Our new sensor overcomes these challenges and marks a major leap forward in the next generation of implantable bioelectronics,” said Dr. Reem Almasri, first author, UNSW School of Biomedical Engineering.

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