Ribbon-like optical fiber shows 1,000-fold pressure sensitivity in lab

A section cut from more than 100m of flat optical fiber carries a laboratory result: it measured pressure with sensitivity up to 1,000 times higher than standard circular fiber designs. Researchers at KTH Royal Institute of Technology in Stockholm and the University of Southampton developed the ribbon-like silica fiber as a new platform for sensing pressure, temperature and other physical changes.

The demonstrated change is in the shape. Rather than flattening a round fiber after manufacture, the team preformed the glass as a high-aspect-ratio ribbon and used laser-based glass processing to build internal features, including air channels and metal fillings. The fiber’s geometry becomes part of the sensor, making the glass itself more responsive to its surroundings.

The researchers also demonstrated a temperature-sensing version by filling part of the internal structure with a tin-based alloy. The platform remains compatible with existing optical systems, while adding mechanical and sensing functions to a technology traditionally used to transmit light.

That matters because optical fibers are lightweight, compact, immune to electromagnetic interference and able to operate in harsh environments. The team sees possible uses in aircraft, drones, bridges, composite materials, biomedical devices, advanced manufacturing and energy systems. In batteries, pressure and temperature changes inside cells could offer early signs of abnormal behavior.

So what, concretely? The immediate result is not a product but a laboratory proof of concept. If the performance holds outside the lab, a fiber could be built into structures or battery systems to sense internal strain, pressure and temperature without relying on electronic sensors. The researchers’ next step is to move toward real systems, including intelligent drones, advanced composites and safer energy technologies.