4 minute read
SMART FIBRES AS ENERGY HARVESTORS AND SENSORS
Walking, jumping, dancing, bending your knees or swinging your arms, with every movement you make you produce mechanical energy. Using smart fibres, you can capture and recover this energy for new applications in healthcare. According to Fatemeh Mokhtari, MSCA Research Fellow in the Biomedical & Tissue Engineering research group at Group T Campus, unseen perspectives and opportunities open here.
By far most mechanical energy harvesting methods are based on piezoelectric materials," Fatemeh explains. "Of these, there are three types: piezoelectric ceramics, piezoelectric polymers and piezoelectric composites. Unlike the energy harvesting utilising solar or thermal energy, performance of piezoelectric generators is not limited to environmental factors."
Recycleerbaar
"Of all these materials, the flexible piezoelectric polymers are the most suitable to serve as a generator," Fatemeh continued.
"It is a non-toxic semi crystalline polymer that is widely applicable for energy harvesting from the human body and use in health monitoring and changing portable medical devices."
Novel approach
Fatemeh studied Textile Engineering at Amirkabir University of Technology-Tehran Polytechnic in Iran She moved to Australia in 2016 to start her PhD at the University of Wollongong.
During her PhD work, she developed a novel approach to create wearable generators and sensors using nanostructured hybrid piezoelectric meltspun fibres. She tested this on a wide variety of textile architectures with embedded fabric-based electrodes. Fatemeh's structure produced a voltage output and power density forty-five times stronger than earlier reported piezoelectric textiles. The developed textile energy harvesting devices were also flexible, lightweight, and consequently very suitable for wearables.
Fatemeh's pioneering work earned her much acclaim in the research community. Her PhD thesis 'Self-Powered Smart Fabrics for Wearable Technologies' was published in full by the publishing house Springer Nature.
After two years as a postdoctoral research fellow at Carbon Nexus at Deakin University’s Institute for Frontier Materials, Fatemeh bagged a coveted and prestigious Marie Curie Fellowship from the European Research Agency in 2024. Since September, she has been working in Leuven.
Health monitoring
At Carbon Nexus, Fatemeh focused on the application of smart piezoelectric medical devices. "Thanks to their high degree of sensitivity, piezoelectric nanocomposite fibres are very suitable for all kinds of human health monitoring," says Fatemeh. As examples, she mentions fall detection, body motion analysis, voice activity monitoring, wearable fitness trackers, cardiovascular and respiration rate monitoring, bed occupancy, movement monitoring and foot pressure analysis.
"Self-powered fibres can also serve as advanced transducers for new cochlear implants," Fatemeh adds. "Piezofibres are capable of converting sound signals and sound vibrations into electric potential. This task is normally performed by the cochlear hair cells. If these cells fail, smart fibres can take over this work.”
Drug delivery
The researchers in the Biomaterials & Tissue Engineering group are also strongly interested in the applications of piezoelectrics in smart drug delivery. "Smart fibres can indeed ensure that the right dose of a drug is delivered at the right time to cells affected by cancer, for example," Fatemeh confirms.
"The condition, however, is that the high-performance piezoelectric fibres must be biodegradable. Additional research is still needed on that point. Common piezoelectric polymers are electrically high performing, but not biodegradable. Those that are biodegradable then lack that strength again. In other words, a solution is needed that can combine the advantages of both types. It is like reconciling water and fire, but that is exactly what makes the research so fascinating.”
Furthermore, Fatemeh also wants to investigate the use of piezoelectronics in bone defect regeneration. "In this, a smart tissue is placed between the broken bones. That tissue stimulates the cell structures of the bones, making the fracture heal faster."
Busy times are ahead for Fatemeh in Leuven, that much is clear. "The challenges are therefore great and numerous," she concludes. "What we develop and make must have high efficiency, a high degree of precision and reliability, a sense of comfort and be flexible, viable for production and affordable."
-Yves Persoons
