Miniaturized springless hybrid nanogenerator for powering portable and wearable electronic devices from human-body-induced vibration

Salauddin, Md,Toyabur, R.M.,Maharjan, P.,Rasel, M.S.,Kim, J.W.,Cho, Hyunok,Park, Jae Yeong Elsevier 2018 Nano energy Vol.51 No.-

<P><B>Abstract</B></P> <P>In this paper, a springless hybridized NG (nanogenerator) was newly designed to have a non-resonant behavior, in which the output power continuously increases with the input frequency and amplitude. To achieve a considerably higher output power generation at low-frequency vibrations and low amplitude, the proposed springless hybrid electromagnetic and triboelectric nanogenerator (SHEMG-TENG) utilizes a dual-Halbach array, which is fabricated with contact-separation and sliding-mode TENGs. The proposed SHEMG-TENG is fabricated and verified from a vibration exciter and human-body-induced vibration. Under the vibration exciter test (horizontal position), the fabricated SHEMG-TENG generated an output current and power of 2.04 mA and 5.41 mW, respectively, which corresponds to a volume power density of 395.4 W/m<SUP>3</SUP> under a matching load resistance of 1.1 KΩ at an applied frequency and acceleration of 6 Hz and 1 g, respectively. For a number of basic human activities such as handshaking, walking, and slow running, the SHEMG-TENG was able to deliver output powers are 2.9 mW, 1.2 mW, and 1.7 mW (horizontal position), respectively, and 1.6 mW, 0.74 mW, and 2.3 mW (vertical position), respectively. This work presents an important step toward realizing SHEMG-TENG from human-body-induced vibration powered to enable wearable and portable smart electronic applications, and is expected to be widely accepted by the general public in their daily lifestyle.</P> <P><B>Highlights</B></P> <P> <UL> <LI> New design and modeling of springless hybrid nanogenerator. </LI> <LI> EMG, contact-separation and sliding mode of TENG. </LI> <LI> Dual Halbach magnet array, nano structured of PTFE, Al grass, and Al porous. </LI> <LI> Higher output-power generation in non-resonant and low-frequency operation. </LI> <LI> Powered wearable and portable electronic devices. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

An impedance tunable and highly efficient triboelectric nanogenerator for large-scale, ultra-sensitive pressure sensing applications

Rasel, M. Salauddin,Maharjan, Pukar,Salauddin, Md.,Rahman, M. Toyabur,Cho, Hyun Ok,Kim, Jae Woo,Park, Jae Yeong Elsevier 2018 Nano energy Vol.49 No.-

<P><B>Abstract</B></P> <P>Precise triboelectric nanogenerators (TENGs) with large-scale pressure sensing ability can be realized by effectively harvesting physical pressure. Extensive research on efficient pressure sensors is ongoing, yet the pressure detection limit and sensitivity of most of the reported pressure sensors are not satisfactory for practical and wearable device applications. Herein, we demonstrate a highly efficient approach toward detecting a wide range of pressures, from 5 kPa to 450 kPa, with a record high sensitivity of 0.51 V/kPa. We aim at maximizing the energy conversion efficiency of 48.17% by optimally tuning the internal impedance of the triboelectric nanogenerator at 2.5 MΩ, because low internal impedance results in high output power. This paper reports the structural design, fabrication, and experimental validation of a self-powered and highly durable TENG pressure sensor for large-scale pressure detection based on double-side tribological layers of micro-patterned polydimethylsiloxane (PDMS) and PDMS-multiwall carbon nanotube (CNT) nanocomposites. An in-sole application of the proposed TENG is demonstrated for varying foot pressures corresponding to different walking patterns, which is likely to be applicable in sports sciences, high-risk diabetic foot ulceration, and rehabilitation. Our present contribution not only facilitates large-scale pressure sensing but also paves the way toward the realization of next-generation self-powered and maintenance-free sensing devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A self-powered triboelectric nanogenerator with record high pressure detection range (From 5 kPa to 450 kPa). </LI> <LI> A maximum of 0.51 V/kPa sensitivity. </LI> <LI> Up to 48.17% energy conversion efficiency. </LI> <LI> Low internal impedance of 2.5 MΩ. </LI> <LI> In-sole application. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Screening of novel alkaloid inhibitors for vascular endothelial growth factor in cancer cells: an integrated computational approach

Shahik, Shah Md.,Salauddin, Asma,Hossain, Md. Shakhawat,Noyon, Sajjad Hossain,Moin, Abu Tayab,Mizan, Shagufta,Raza, Md. Thosif Korea Genome Organization 2021 Genomics & informatics Vol.19 No.1

Vascular endothelial growth factor (VEGF) is expressed at elevated levels by most cancer cells, which can stimulate vascular endothelial cell growth, survival, proliferation as well as trigger angiogenesis modulated by VEGF and VEGFR (a tyrosine kinase receptor) signaling. The angiogenic effects of the VEGF family are thought to be primarily mediated through the interaction of VEGF with VEGFR-2. Targeting this signaling molecule and its receptor is a novel approach for blocking angiogenesis. In recent years virtual high throughput screening has emerged as a widely accepted powerful technique in the identification of novel and diverse leads. The high resolution X-ray structure of VEGF has paved the way to introduce new small molecular inhibitors by structure-based virtual screening. In this study using different alkaloid molecules as potential novel inhibitors of VEGF, we proposed three alkaloid candidates for inhibiting VEGF and VEGFR mediated angiogenesis. As these three alkaloid compounds exhibited high scoring functions, which also highlights their high binding ability, it is evident that these alkaloids can be taken to further drug development pipelines for use as novel lead compounds to design new and effective drugs against cancer.

Electromagnetic energy harvester based on a finger trigger rotational gear module and an array of disc Halbach magnets

Kim, Jae Woo,Salauddin, Md,Cho, Hyunok,Rasel, M. Salauddin,Park, Jae Yeong Elsevier 2019 APPLIED ENERGY Vol.250 No.-

<P><B>Abstract</B></P> <P>We propose a non-resonant finger-triggered electromagnetic energy harvester (EMEH) using multiple gear modules and an array of disc Halbach magnets, which can generate significant voltage and power under low input-frequency vibrations. The proposed EMEH converts the applied low frequencies into higher frequencies using a multiplying gear module and forwards the linear excitation to a rotational module by gear parts. The multiplying gear module was used for increasing the speed of magnet motion. In the energy generation part, an array of disc Halbach magnets were used for concentrating the magnetic flux toward the coils. The proposed energy harvester generated an open-circuit voltage of 1.39 V at an average power of 7.68 mW, with an optimal load of 36 Ω at an input frequency of 3 Hz. The prototype harvester offers a power density of 0.833 mWcm<SUP>−3</SUP>, which is much higher than those of recently reported EMEHs. We demonstrate wearable and portable electronics such as a stopwatch and pedometer-based on finger triggering. This study presents an important step toward low-frequency-vibration-powered devices for portable smart electronic applications and is expected to be widely applicable.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Finger-triggered EMEH using gear modules and Halbach magnets array. </LI> <LI> Non-resonant output behavior of the EMEH. </LI> <LI> Frequency up conversion through multiple gear module. </LI> <LI> Low-frequency vibration based EMEH for portable smart electronics application. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Natural wind-driven ultra-compact and highly efficient hybridized nanogenerator for self-sustained wireless environmental monitoring system

Rahman, M. Toyabur,Salauddin, Md,Maharjan, P.,Rasel, M.S.,Cho, Hyunok,Park, Jae Yeong Elsevier 2019 Nano energy Vol.57 No.-

<P><B>Abstract</B></P> <P>Owing to the climate change and energy crisis, harvesting energy from our surroundings and the construction of self-powered wireless environmental monitoring systems are promising approaches in modern times. In this paper, an ultra-compact highly efficient miniaturized windmill comprising a hybridized nanogenerator (MW-HNG) is reported based on three conversion mechanisms <I>i.e.</I> triboelectric nanogenerator (TENG), piezoelectric nanogenerator (PENG), and electromagnetic generator (EMG). The MW-HNG is designed as a 3D-printed fully-enclosed structure for the natural wind energy harvesting by converting into rotational motion: all harvesting units reside in a common rotation system to effectively and simultaneously produce electricity. At a wind speed of 6 m/s, the flexible-blade-based hybridization-mode (contact–lateral sliding–separation–contact) TENG and coupled PENG can generate maximal power values of 1.67 mW and 1.38 mW at optimal load resistances of 10 MΩ and 330 KΩ, respectively. In contrast, the multipole-magnet-based EMG can obtain a maximal output power of 268.6 mW at 180 Ω. The MW-HNG demonstrates a quick charging ability for capacitors and the capability to feed hundreds of LEDs. Further, a self-powered wireless sensor system is developed for real-time environmental monitoring by combining an MW-HNG, a customized power management circuit, and wireless sensor unit (a smartphone to display sensor data). Our proposed MW-HNG is suitable for self-powered wireless sensor networks (WSNs) in the subway system by generating high-power electrical output from moving-induced wind mechanical energy.</P> <P><B>Highlights</B></P> <P> <UL> <LI> 3D-printed fully-enclosed hybridized nanogenerator for wind energy harvesting. </LI> <LI> Integrated three popular conversion mechanisms into a single energy harvesting unit. </LI> <LI> Flexible-blade-based hybridizing TENG, coupled PENG and multipole-magnet-based EMG. </LI> <LI> Potential application in subway system for illuminating billboard and animated LEDs. </LI> <LI> Self-powered wireless environmental sensor with real-time monitoring <I>via</I> smartphone. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Nanogenerator for scavenging low frequency vibrations

Park, Jae Yeong,Salauddin, Md,Rasel, M Salauddin IOP 2019 Journal of micromechanics and microengineering Vol.29 No.5

<P>Energy harvesting technologies have being developed swiftly in the last couple of years owing to the recent developments of low power consuming features of portable and wearable electronic devices. For operating these devices and systems, eco-friendly and low frequency vibration based nanogenerators have been researched and developed. The major reason behind this rapid growth of such nanogenerators is the abundance of low frequence vibrations, which exist almost everywhere and have the potential to be easily harvested by many different transduction mechanisms. This paper reviews the key ideas and performances of these reported nanogenerators for scavenging energy from low frequency vibrations. In addition, various types of vibration sources, approaches, device architectures, materials, fabrications and practical applications of these energy scavenging devices are also reviewed.</P>

A fully enclosed, 3D printed, hybridized nanogenerator with flexible flux concentrator for harvesting diverse human biomechanical energy

Maharjan, Pukar,Cho, Hyunok,Rasel, M. Salauddin,Salauddin, Md.,Park, Jae Yeong Elsevier 2018 Nano energy Vol.53 No.-

<P><B>Abstract</B></P> <P>Human body motion is highly regarded as a promising source of energy for powering body-worn electronic devices and health monitoring sensors. Transforming the human biomechanical energy into an electrical energy provides a sustainable energy to drive those devices and sensors, reducing their battery dependency. This work presents a fully-enclosed wrist-wearable hybridized electromagnetic-triboelectric nanogenerator (FEHN) for effectively scavenging energy from the low-frequency natural human wrist-motion (≤ 5 Hz). The FEHN incorporates the rolling electrostatic induction and electromagnetic induction using a freely moving magnetic ball inside a hollow circular tube. The materials used in 3D printing technology are used as energy harvesting material for easy, quick and worthwhile fabrication of the FEHN. A thin flexible flux concentrating material is introduced to increase the emf and enhances the electromagnetic output performance. The FEHN can harvest energy under the diverse circumstances and irregular wrist-motions, such as swinging, waving, shaking, etc. Following the experiments, the FEHN achieves an average power density of 0.118 mW cm<SUP>−3</SUP> and can drive a commercial wrist-watch continuously for more than 23 min from just 5 s of wrist motion. This successful demonstration renders an effective approach for scavenging wasted biomechanical energy and provides a promising solution towards the development of sustainable power supply for wearable electronic devices and self-powered healthcare monitoring sensors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A fully enclosed, 3D printed and hybridized nanogenerator, isolated from external environment is newly developed </LI> <LI> Sustainable nanogenerator for powering body-worn wearable electronic devices and healthcare monitoring sensors. </LI> <LI> Highly capable of harvesting energy from diverse wrist motions such as swinging, waving, shaking, twisting, etc. </LI> <LI> A flexible FeSiCr/PDMS composite based flux concentrator around the copper coil is applied to increase the induced emf. </LI> <LI> 5 s of wrist motion is enough to power a commercial electronic wrist-watch for more than 23 min continuously. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A miniaturized electromagnetic vibration energy harvester using flux-guided magnet stacks for human-body-induced motion

Halim, Miah A.,Cho, Hyunok,Salauddin, Md.,Park, Jae Y. Elsevier Sequoia 2016 Sensors and actuators. A Physical Vol.249 No.-

<P><B>Abstract</B></P> <P>We present a miniaturized electromagnetic energy harvester (EMEH) that uses two flux-guided magnet stacks to harvest energy from common human-body-induced motions such as hand-shaking, walking, and slow running. We designed each magnet stack to increase the flux density within a given size of the harvester component, by guiding the flux lines through soft magnetic material and designed the miniaturized EMEH to up-convert the low-frequency vibration generated by human-body-induced motion to a high-frequency vibration by mechanical impact of a spring-less structure. Our use of a spring-less structure eliminates the challenges of designing a practical and reliable low-frequency (<5Hz) oscillator. Our low-frequency oscillator couples the human-body-induced vibration to two high-frequency oscillators (electromagnetic transducer elements). Each high-frequency oscillator consists of the analyzed 2-magnet stack and customized helical compression spring. We fabricated a standard AAA battery sized prototype (3.9cm<SUP>3</SUP>) and tested it with different human activities. We were able to generate a maximum 203μW, 32μW, and 78μW average power from hand-shaking, walking, and slow running motion, respectively. This miniaturized structure yields a maximum average power density of 52μWcm<SUP>−3</SUP>. We used a rectifier and multiplier circuit as the interface between the harvester and a wearable electronic load (wrist watch) to demonstrate the feasibility and capability of powering small-scale electronic systems from human-body vibration.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A human-motion driven miniaturized EM energy harvester using flux-guided magnet stacks. </LI> <LI> Flux-guided magnet stack increases the power density more than three times. </LI> <LI> Capable of driving wearable electronics through efficient power conditioning circuitry. </LI> </UL> </P>