Defence D. Sengupta: "Interfacing biomimetics and nanomaterials for next generation wearables"

Promotors: Prof. Yutao Pei and Dr. Ajay Kottapalli

Abstract: With the steady rise in average life expectancy across the globe in the last century, lifestyle related diseases are causing a burden on existing healthcare infrastructure. Emerging complex diseases cause significant impact on productive man hours and burden the existing healthcare system. For instance, people suffering from progressive neurodegenerative disorders like Parkinson’s disease, multiple sclerosis, and Huntington’s disease must be monitored frequently to track the progress of the diseases. Due to the life altering nature of these neurodegenerative diseases, it becomes very difficult for the patients to return to their daily routine, considering the fact that a significant amount of their time is spent in hospital-based diagnostic and rehabilitation centres. Other less serious complications, like sleep apnoea, post-trauma recovery, and similar conditions also need regular progress tracking and medical intervention (if necessary) and can cause disruptions to daily life due to frequent hospital stays. Inexpensive, accurate, and power efficient wearable sensors will be playing a major role in facilitating the health 3.0 in the foreseeable future. Particularly, the onslaught of COVID-19 pandemic since late 2019 have fuelled the demand for wearable sensors capable of human physiological vitals monitoring.

The need of the hour is efficient, non-invasive, wearable sensors capable of gathering vital human physiological parameters round the clock and store the data in cloud for remote access by healthcare specialists. However, for any sensor to be considered seriously in healthcare space, parameters like sensitivity, ease of use, cost effectiveness, long term reliability and most importantly, low power budget are of paramount importance. Other than applications in human physiological monitoring, flexible sensors are relevant for applications involving artificial skins for next generation prosthesis, soft human-machine interface, and robotics assisted medical facilities.

Nature is full of unique designs to tackle interesting problems we encounter daily. For instance, the seamless entry of a Kingfisher from a low resistance medium (air) to a high resistance medium (water) is nothing short of an extraordinary aerodynamic design marvel. Interfacing nanotechnology with biomimetics is important in the context of next generation wearables as it can lead to the development of a class of highly reliable and inexpensive wearable sensors tailored to cater the urgent needs of physiological parameter monitoring.

This thesis has been a humble effort towards creating a seamless integration between the concepts of bioinspiration and Microsystems-enabled miniaturized sensors for tackling a wide variety of problems we encounter in our daily life. Two most widely used and traditional mechanisms of sensing entailing piezoresistive and capacitive sensing were investigated and a bioinspiration approach was taken to device next generation flexible and wearable devices. A wide variety of practical problems ranging from human gait monitoring to low powered flow sensing has been tackled taking inspiration from nature.

Dissertation