Sajib Roy
Academic and research departments
Nanoelectronics Centre, Advanced Technology Institute, School of Computer Science and Electronic Engineering, Faculty of Engineering and Physical Sciences.About
My research project
Energy harvesting and self-powering for medical implanted devicesImplantable medical devices (IMDs) are widely utilised to monitor body functions, drug delivery, cell stimulation, etc. However, these IMDs have as of yet not been self-powered. With their regular power needs, typically supplied by conventional batteries, it has introduced a bottleneck, with social, financial and physical inconveniences to the patients. The main aim of this research is to harvest biomechanical energies including body movements, internal organ motions, and daily human activities, via triboelectric nanogenerator (TENG) technology and employ it to operate the IMDs in autonomous mode without the need of a solid-state battery. TENGs are a new type of energy harvester that operate on the principle of contact electrification of dissimilar material surfaces, whose charge then can be consolidated and used to move a current through a load. Our research shows the output current from TENGs is double-peaked impulses with high voltage (100-500V) and power density of 1-20 mW/cm2, that can be coupled with the power requirements of IMDs. In order to achieve these goals, the research will develop wearable, biocompatible, and skin-friendly intelligent plaster-like TENGs by utilising electro-spun micro/nano-fibrous scaffolds from nature-driven materials (i.e., silk & cotton) and synthetic polymers (i.e., polyimide, PVDF-TrFE, and PEDOT:PSS). The Advanced Technology Institute (ATI) has world leading activities in both these areas.
This research conducted will involve several objectives including:
-optimization of the electrospinning synthesis process; so that the material can withstand and operate under harsh/outdoor environmental and in vivo body implanted conditions
-optimization of device structures; so that it can be easily adopt into various human body shapes and efficiently harvest the biomechanical activities
-optimizing the internal resistance of the device; so that it can match and fulfil the power requirement of IMDs, including external communication links on an intermittent basis
This project will also help target novel energy sources for the IoT sector to power small to medium-size devices in the micro- and milli-Watt range. Furthermore, as waste energy is captured, the potential gain of energy and reduced impact of this waste energy on the environment will help UK sustainability and healthy society impact on the SDG.
Supervisors
Implantable medical devices (IMDs) are widely utilised to monitor body functions, drug delivery, cell stimulation, etc. However, these IMDs have as of yet not been self-powered. With their regular power needs, typically supplied by conventional batteries, it has introduced a bottleneck, with social, financial and physical inconveniences to the patients. The main aim of this research is to harvest biomechanical energies including body movements, internal organ motions, and daily human activities, via triboelectric nanogenerator (TENG) technology and employ it to operate the IMDs in autonomous mode without the need of a solid-state battery. TENGs are a new type of energy harvester that operate on the principle of contact electrification of dissimilar material surfaces, whose charge then can be consolidated and used to move a current through a load. Our research shows the output current from TENGs is double-peaked impulses with high voltage (100-500V) and power density of 1-20 mW/cm2, that can be coupled with the power requirements of IMDs. In order to achieve these goals, the research will develop wearable, biocompatible, and skin-friendly intelligent plaster-like TENGs by utilising electro-spun micro/nano-fibrous scaffolds from nature-driven materials (i.e., silk & cotton) and synthetic polymers (i.e., polyimide, PVDF-TrFE, and PEDOT:PSS). The Advanced Technology Institute (ATI) has world leading activities in both these areas.
This research conducted will involve several objectives including:
-optimization of the electrospinning synthesis process; so that the material can withstand and operate under harsh/outdoor environmental and in vivo body implanted conditions
-optimization of device structures; so that it can be easily adopt into various human body shapes and efficiently harvest the biomechanical activities
-optimizing the internal resistance of the device; so that it can match and fulfil the power requirement of IMDs, including external communication links on an intermittent basis
This project will also help target novel energy sources for the IoT sector to power small to medium-size devices in the micro- and milli-Watt range. Furthermore, as waste energy is captured, the potential gain of energy and reduced impact of this waste energy on the environment will help UK sustainability and healthy society impact on the SDG.
My qualifications
ResearchResearch interests
Triboelectric Nanogenerators, 2D Nanomaterials, Electrospinning, Wearable Medical Devices, Self-powered Sensors, Sleep Monitoring
Research interests
Triboelectric Nanogenerators, 2D Nanomaterials, Electrospinning, Wearable Medical Devices, Self-powered Sensors, Sleep Monitoring
Sustainable development goals
My research interests are related to the following:
Publications
In this paper, we report a wind energy harvesting system for Internet of Things (IoT)-based environment monitoring (e.g., temperature and humidity, etc.) for potential agricultural applications. A wind-driven electromagnetic energy harvester using rotational magnet pole-pairs (rotor) with a back-iron shield was designed, analyzed, fabricated, and characterized. Our analysis (via finite element method magnetic simulations) shows that a back-iron shield enhances the magnetic flux density on the front side of a rotor where the series connected coils interact and convert the captured mechanical energy (wind energy) into electrical energy by means of electromagnetic induction. A prototype energy harvester was fabricated and tested under various wind speeds. A custom power management circuit was also designed, manufactured, and successfully implemented in real-time environmental monitoring. The experimental results show that the harvester can generate a maximum average power of 1.02 mW and maximum power efficiency of 73% (with power management circuit) while operated at 4.5 m/s wind speed. The system-level demonstration shows that this wind-driven energy harvesting system is capable of powering a commercial wireless sensor that transmits temperature and humidity data to a smartphone for more than 200 min after charging its battery for only 10 min. The experimental results indicate that the proposed wind-driven energy harvesting system can potentially be implemented in energetically autonomous IoT for smart agriculture applications.
Triboelectric nanogenerator (TENG) represents a major advancement in capability for self-powered sensors, with its ability to convert low-frequency mechanical movements into electricity. These devices serve at present an unmet medical and societal need in the monitoring of human activity and enhancing interactions between humans and machines, the optioned interface for setting up verifiable digital twins. Here, a novel composite nanofibrous TENG (CNF-TENG) based on borophene@poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) is constructed through electrospinning. Comprehensive materials characterization of the exfoliated nanosheets confirms crystalline sheet morphology and validates their incorporation into the fibers. The inclusion of borophene introduces a dual innovation by enhancing both the jet stressing in electrospinning and the quality of doped films. This improvement is attributed to the enhanced effective permittivity through interfacial polarization, which promotes β-phase formation, electron-donating capacity, surface charge trapping, and refined fiber morphology, while inducing a transition from a hydrophobic to a superhydrophobic surface state. When paired with nylon 66 nanofibers, the CNF-TENG exhibits a remarkable sensitivity of 53.8 ± 1.2 V kPa−1, and a power density of 1.2 W m−2, representing a 13-fold enhancement over pristine PVDF-HFP. An array of 16 ultra-sensitive CNF-TENG sensors for possible use in dementia monitoring and sleep disorder mitigation is successfully demonstrated, giving various sleep patterns and physiological data sets.