INST new tech to create cost-effective devices for wearable applications

New Delhi: A team of researchers from the Institute of Nano Science and Technology (INST) Mohali, an autonomous institute of the Department of Science and Technology, have developed a new technology that can help create cost-effective devices for wearable applications.

Their droplet microfluidics technology will help produce microspheres with a high electroactive (EA) phase that can lead to piezoelectric devices for wearable applications, serving as self-powered sensors for monitoring diverse physiological signals.

“Integration of this technology into wearables opens new pathways for efficient energy harvesting from human motion, paving the way for sustainable and self-sufficient wearable devices,” said the researchers.

“The method offers numerous advantages, including simplicity, cost-effectiveness, high efficiency, and control, making it highly significant for applications in the biomedical sector, self-powered devices, and beyond,” they added. The technology, when combined with the off-chip thermal polymerisation technique, helps synthesise tunable Polyvinylidene fluoride (PVDF) microspheres to engineer a high EA phase. Polymer microspheres, notable for their increased surface area and enhanced interface capabilities, have attracted substantial interest. However, existing methods for their production possess drawbacks such as shape irregularities and high energy requirements. To address these limitations, microfluidic techniques have emerged, offering benefits like tunability, size and shape control, and efficiency. Over the past years, microspheres of PVDF have been produced via microfluidics but the presence of high EA phase in them remains a challenge.

In the study, the team from INST engineered the high EA phase of microspheres through flow rates of oil and polymer solution in the microfluidic device and extensive characterisation was carried out to verify the piezoelectric response of the microspheres. The team brought about uniformity and size control (126-754 micrometres) of the microspheres. By adjusting flow rates and optimising reaction temperature, the EA phase was enhanced to around 82 per cent.

In addition, artificial intelligence (AI) was used as a vital tool in enabling accurate predictions for microsphere diameter and phases, reducing the need for extensive laboratory optimisation before droplet generation in microfluidics. The study was recently published in the Chemical Engineering Journal.