Scientists have developed new technology that can help fabricate cost-effective and efficient piezoelectric devices for self-powered wearable devices that harvest energy from the human body to monitor diverse physiological parameters.
Piezoelectric devices are based on electric charge that accumulates in certain solid materials, such as crystals and ceramics, as well as biological matter, such as bone or various proteins, in response to applied mechanical stress. Researchers at the Institute of Nano-Science and Technology (INST), Mohali, have found a technique in the field of microfluidics to produce microspheres that are tiny solids or hollow spheres of a protein or synthetic polymer with a high electro-active phase that can be used in piezoelectric devices.
Polymer microspheres are known for their increased surface area and enhanced interface capabilities; however, the existing methods for their production have several drawbacks, such as shape irregularities and high energy requirements.
To address these limitations, microfluidic techniques have emerged, offering benefits such as tunability, size and shape control, and efficiency. Researchers at INST addressed the technical challenges by combining microfluidics technology with off-chip thermal polymerisation techniques to produce microspheres that exhibited uniformity and monodispersity.
Artificial intelligence (AI) was also used as a vital tool in enabling accurate predictions for microsphere diameter and phases, reducing the need for extensive laboratory optimisation prior to droplet generation in microfluidics.
As a proof of concept, the researchers explored the application of polyvinylidene fluoride (PVDF) microspheres in the development of a flexible piezoelectric device that can seamlessly integrate with different parts of the human body, like the elbow, knee, etc., through wearables.
It underwent varying degrees of compression at different rates, depending on specific body movements, harnessing the energy generated by body movements that would otherwise go to waste. This generated electrical response proved to be substantial, providing enough output voltage to operate low-power devices. Source: TNS