Wearable Optics gets new breakthrough from Chinese University
Wearable Sensors, clothes you can wear that can help athletes and physical therapists track your vitals more completely, aiding in treatment and training, just got a boost recently with a a research project out of Tsinghua University in Beijing that demonstrates how optical fibers can be made sturdy enough to wear, while also being equipped to collect a wide range of data that will equip trainers and doctors in maximizing their therapy and/or training efforts.
From Science Daily
The exciting applications of wearable sensors have sparked a tremendous amount of research and business investment in recent years. Sensors attached to the body or integrated into clothing could allow athletes and physical therapists to monitor their progress, provide a more detailed level of motion capture for computer games or animation, help engineers build robots with a lighter touch or form the basis for new types of real-time health monitors.
In Optica, The Optical Society’s journal for high impact research, a team led by Changxi Yang of the State Key Laboratory of Precision Measurement Technology and Instruments at Tsinghua University in Beijing offers the first demonstration of optical fibers sturdy enough to sense a wide range of human motion.
The new fiber is sensitive and flexible enough that it can detect joint movements, unlike currently used fiber sensors. “This new technique provides a fiber-optic approach for measuring extremely large deformations,” said Yang. “It’s wearable, mountable and also possesses intrinsic advantages of optical fibers such as inherent electrical safety and immunity to electromagnetic interference.”
Trouble with stretching
Optical fibers have been used for strain sensing on bridges and buildings for years; stretch or bend the fiber a little and light going through it is shifted in a way that can be easily picked up by a monitor. Traditionally optical fibers haven’t been the best choice for strain sensing on the human body because they are typically made of plastic or glass, which are stiff and don’t bend well. A silica glass fiber, for example, can handle a maximum strain of less than 1 percent, while a bending finger joint would strain it by more than 30 percent.
This barrier has meant that most wearable sensor developments so far have been based on electronic sensors. These sensors detect movement by measuring changes in electrical properties such as resistance as the sensor bends. However, these systems are difficult to miniaturize, can lose their electrical charge and are sensitive to electromagnetic interference from devices such as cars and cell phones. A bendable optical fiber could avoid these problems and potentially create wearable devices that are more stable and sustainable than those based on electronics.