IIT (ISM) Dhanbad Researchers Patent Temperature-Independent 2D Optical Tilt Sensor

IIT (ISM) Dhanbad researchers have secured a patent for a temperature-independent optical sensor designed to measure the tilt of structures and equipment in two directions, potentially offering a compact and lightweight solution for long-term monitoring.

The technology, titled “Temperature Independent 2-D Optical Tilt Sensor,” was developed by Associate Professor Dr Amitesh Kumar and research scholar Randhir Kumar Sah from the institute’s Electronics Engineering Department. The patent application, numbered 202531011041, was filed on February 10, 2025, and has been published as an Indian patent application. The sensor uses Fiber Bragg Grating (FBG) technology, where changes in light travelling through a specially patterned optical fibre are used to detect movement. Its design combines a glass-fibre-based rectangular arm with a suspended spherical pendulum inside a compact enclosure, enabling inclination measurement along two axes.

Temperature independence is a key feature because fluctuations in temperature can affect conventional mechanical and optical sensors by changing material dimensions or optical responses, potentially causing measurement errors. Minimising such effects is particularly important for outdoor infrastructure and industrial environments exposed to varying temperatures. The institute said the sensor is lightweight, resistant to electromagnetic interference and suitable for harsh environments. Its potential applications include structural health monitoring, industrial automation, robotics, aerospace, medical equipment and geotechnical systems.

However, publicly available information does not specify the device’s measurement accuracy, angular range, production cost or quantified cost advantage. There is also no publicly documented confirmation of large-scale field testing of the newly patented design. These parameters will be important in determining its commercial and deployment readiness. The innovation builds on the researchers’ work in FBG-based sensing, including temperature-independent displacement sensing and inclination measurement.

Future development could focus on field validation, accuracy and range optimisation, ruggedisation and integration with remote monitoring systems. Such advances could help move the technology from laboratory development towards practical deployment in bridges, machinery, aerospace systems and other critical infrastructure.