Issue 2
Vibrant@FENG - Issue 2 (December 2021)
The development of microscopic optical fibre sensors with pioneering biomedical monitoring capability
PolyU has made a breakthrough development in optical fibre sensors, making the advanced railway safety monitoring technologies available for medical surveillance inside the human body. Applications include improving surgery precision, providing novel ways of monitoring human body recovery from within the body, smart cochlear implantation, bone fracture recovery monitoring, and navigation monitoring in cardiac catheterisation.
The research team led by Professor Hwa-yaw Tam, Chair Professor of Photonics and Head of the Department of Electrical Engineering at PolyU, developed the novel fibre optic microsensors that are biocompatible, supple and extremely sensitive to very small pressure changes inside the human body. Traditional optical fibres made of glass or plastic have major drawbacks – glass is too stiff and brittle, while traditional plastic fibres tend to absorb water.
Professor Tam's team made a critical breakthrough by basing their novel fibre optic sensors on an advanced plastic material, ZEONEX, that solves the glass and traditional plastic problems. In addition, the new sensor is made more sensitive by adding a side hole running in parallel with the light transmission path inside the optical fibre. The new "Side Hole Polymer Optical Fibre Sensors" are biocompatible and can be made as small as a few micrometres. Their pressure sensitivity is 20 times that of traditional optical fibre sensors. "The new plastic sensors are humidity insensitive, supple and shatter-resistant. They are also chemically inert, biocompatible, and can be made super tiny in size. These unique features make the sensors ideal for integration with medical implants," Professor Tam said.
The research team is currently working with counterparts from Australian and Japanese universities to develop various sensors for medical monitoring applications, such as smart cochlear implants that could provide critical information about location and force to surgeons in real time during an implantation procedure, as well as orthopaedic implants for monitoring bone fracture recovery.
The PolyU research team will also continue to explore further medical monitoring applications using the new sensors, including their use for precise navigation and shape detection in cardiac catheterisation. They are also expanding the sensors’ ability to measure other physical or chemical changes such as acidity and temperature.
