Research

Research Interests & Publications

Envisioning a future where wearable bioelectronics transforms healthcare with continuous monitoring, early diagnosis, and personalized treatments.

Research Areas

Wearable Electronics

Wearable Electronics

Designing flexible, skin-like devices (e.g., e-tattoos) for continuous monitoring of signals like EEG, EMG, and ECG, enhanced with AI for early diagnosis and personalized care.

Advanced Manufacturing

Advanced Manufacturing

Developing high-performance wearable devices using techniques like 3D printing, screen printing, and electrospinning—integrated with advanced materials like graphene, CNTs, and MXenes for enhanced sensitivity, flexibility, and biocompatibility.

Translational Devices

Translational Devices

Turning research into real-world solutions by integrating wearable systems with mobile platforms and wireless tech for clinical and remote health applications.

Publications

Showing 41 of 41 publications
2024
Journal Article

On-scalp printing of personalized electroencephalography e-tattoos

Luize Scalco de Vasconcelos, Yichen Yan, Pukar Maharjan, Satyam Kumar, Minsu Zhang, Bowen Yao, Hongbian Li, Sidi Duan, Eric Li, Eric Williams, Sandhya Tiku, Pablo Vidal, R. Sergio Solorzano-Vargas, Wen Hong, Yingjie Du, Zixiao Liu, Fumiaki Iwane, Charles Block, Andrew T. Repetski, Philip Tan, Pulin Wang, Martín G. Martín, José del R. Millán, Ximin He, Nanshu Lu

This paper presents a groundbreaking advancement in noninvasive brain-monitoring: on-scalp digital printing of custom-designed, temporary-tattoo-like sensors. This approach overcomes the limitations of traditional EEG systems by using material innovations and non-contact printing to fabricate self-drying, ultrathin e-tattoos compatible with hairy scalps, enabling comfortable, long-term, high-quality brain activity monitoring.

Cell Biomaterials
2024
Review Article

E-Tattoos: Toward Functional but Imperceptible Interfacing with Human Skin

Hongbian Li, Philip Tan, Yifan Rao, Sarnab Bhattacharya, Zheliang Wang, Sangjun Kim, Susmita Gangopadhyay, Hongyang Shi, Matija Jankovic, Heeyong Huh, Zhengjie Li, Pukar Maharjan, Jonathan Wells, Hyoyoung Jeong, Yaoyao Jia, Nanshu Lu

This review article offers an exhaustive exploration of e-tattoos, which are ultrathin, skin-soft wearable electronics that enable noninvasive and comfortable lamination on human skin. It covers their materials, structures, manufacturing processes, properties, functionalities, applications, and remaining challenges, with the potential to revolutionize telemedicine, mobile health, and human-machine interactions.

Chemical Reviews
2024
Journal Article

Recent Progress in Wearable Triboelectric Nanogenerator for Advanced Health Monitoring and Rehabilitation

Puran Pandey, Pukar Maharjan, Min-Kyu Seo, Keshav Thapa, Jung Inn Sohn

This review provides an overview of recent developments in wearable TENGs for healthcare applications. It discusses how TENGs work and explores a wide range of self-powered health monitoring and rehabilitation applications. The paper summarizes advancements in materials and design features to help create efficient, accurate, and practical bioapplicable technology, while also discussing challenges and prospects.

International Journal of Energy Research
2023
Journal Article

Brachistochrone Bowl-Inspired Hybrid Nanogenerator Integrated with Physio-Electrochemical Multi-Sensors for Self-Sustainable Smart Pool Monitoring Systems

Pukar Maharjan, Trilochan Bhatta, Xue Hi, Gagan B. Pradhan, Hyesu Song, Kumar Shrestha, Jae Y. Park

This paper proposes a self-sustainable smart pool monitoring system that continuously monitors various physio-electrochemical properties of pool water in real-time without external power. The system includes an electromagnetic generator inspired by the Brachistochrone bowl to harvest energy from random water motion, powering a wireless transmission unit and a multifunctional sensor unit.

Advanced Energy Materials
2022
Journal Article

A High-Performance Rotational Energy Harvester Integrated with Artificial Intelligence-Powered Triboelectric Sensors for Wireless Environmental Monitoring System

K. Shrestha, Pukar Maharjan, T. Bhatta, S. Sharma, MT Rahman, S. Lee, Md Salauddin, SMS Rana, Jae Y. Park

This paper proposes a high-performance rotational energy harvester using a circular Halbach array magnet to prevent flux leakage and concentrate magnetic flux. This design leads to a fourfold increase in magnetic flux density over conventional magnets. The harvested power is used to drive a complete IoT system for self-powered wireless environmental monitoring, which includes an AI-powered system for wind speed prediction.

Advanced Engineering Materials
2022
Journal Article

A 3D Printed Compact and Intelligent Power Module Based on Vibration Energy Harvester Integrated with Self-Powered Triboelectric Sensor for Industry 4.0 IoT Applications

Pukar Maharjan, Sanghyun Lee, Trilochan Bhatta, Gagan B. Pradhan, Kumar Shrestha, Seonghoon Jeong, SM Sohel Rana, Jae Yeong Park

This paper proposes a compact, vibration-driven intelligent power module for Industry 4.0 IoT applications. It integrates a 3D-printed electromagnetic vibration energy harvester (VEH) with a triboelectric-based self-powered vibration sensor (SVS) for excellent energy harvesting and real-time condition monitoring. The module is designed to be the size of a standard D-battery.

Advanced Material Technologies
2022
Journal Article

A Siloxene/Ecoflex Nanocomposite-Based Triboelectric Nanogenerator with Enhanced Charge Retention by MoS2/LIG for Self-Powered Touchless Sensor Applications

Kumar Shrestha, Sudeep Sharma, Gagan B.Pradhan, Trilochan Bhatta, Pukar Maharjan, SM Sohel Rana, Sanghyun Lee, Sookyeong Seonu, Youngdo Shin, Jae Y. Park

This paper proposes a high-performance contactless TENG based on a Siloxene/Ecoflex nanocomposite, which induces abundant surface charges due to its strong electron affinity. To address the challenge of charge retention, a MoS₂ incorporated laser-induced graphene (LIG) is introduced as a charge trapping interlayer, which increases the surface potential four-fold and enhances the TENG's output performance.

Advanced Functional Materials
2022
Journal Article

Polyaniline-nanospines engineered nanofibrous membrane based piezoresistive sensor for high-performance electronic skins

Sudeep Sharma, Ashok Chhetry, Pukar Maharjan, Shipeng Zhang, Kumar Shrestha, Md Sharifuzzaman, Trilochan Bhatta, Youngdo Shin, Dongkyun Kim, Sanghyun Lee, Jae Y Park

This paper proposes a highly sensitive hybridized nanofibrous membrane-based pressure sensor to overcome the limitations of existing piezoresistive sensors. Polyaniline (PANI)-nanospines are uniformly deposited on hybrid hierarchical nanofibers, achieving high sensitivity over a broad pressure range, making it suitable for electronic skin (e-skin) applications.

Nano Energy
2021
Journal Article

A Hybrid Self-Powered Arbitrary Wave Motion Sensing System for Real-Time Wireless Marine Environment Monitoring Application

Trilochan Bhatta, Pukar Maharjan, Kumar Shrestha, Sanghyun Lee, Md Salauddin, M Toyabur Rahman, SM Sohel Rana, Sudeep Sharma, Chani Park, Sang Hyuk Yoon, Jae Yeong Park

This paper presents an effective approach that simultaneously generates power from arbitrary motion waves and can sense and wirelessly transmit wave information without an external supply. The hybridized ellipsoidal device, inspired by the elliptical trajectory of objects over shallow water waves, consists of six planar spiral coils for power generation and four magnetic force-actuated TENGs as self-powered wave motion sensors.

Advanced Energy Materials
2021
Journal Article

Fabric-Assisted MXene/Silicone Nanocomposite-Based Triboelectric Nanogenerators for Self-Powered Sensors and Wearable Electronics

Md Salauddin, SMS Rana, MT Rahman, Md Sharifuzzaman, Pukar Maharjan, Trilochan Bhatta, Hyunok Cho, Sanghyun Lee, Chani Park, Kumar Shrestha, Sudeep Sharma, Jae Yeong Park

This paper introduces a novel, scalable surface modification method using a fabric-assisted micropatterning technique on a highly negative MXene/silicone nanocomposite surface. This method boosts the output performance of TENGs for self-powered sensors and wearable electronics. The technique is simple, requiring no special equipment.

Advanced Functional Materials
2021
Journal Article

Cobalt-Nanoporous Carbon Functionalized Nanocomposite-Based Triboelectric Nanogenerator for Contactless and Sustainable Self-Powered Sensor Systems

SM Sohel Rana, Md Abu Zahed, MT Rahman, M. Salauddin, Sang Hyun Lee, Chani Park, Pukar Maharjan, Trilochan Bhatta, Kumar Shrestha, Jae Yeong Park

To address the drawbacks of contact-mode TENGs, such as wear and noise, and the need for contactless sensors post-COVID-19, this work explores MOF-based Nanoporous Carbon (NPC) materials. Co-NPC particles, synthesized from ZiF-67, are used to create a nanocomposite dielectric, improving charge storage and reducing charge dissipation in a contactless single-electrode TENG.

Advanced Functional Materials
2021
Journal Article

Cation functionalized nylon composite nanofibrous mat as a highly positive friction layer for robust, high output triboelectric nanogenerators and self-powered sensors

SM Sohel Rana, MT Rahman, S Sharma, M Salauddin, Sanghyuk Yoon, Chani Park, Pukar Maharjan, Trilochan Bhatta, Jae Yeong Park

This paper proposes a poly(diallyldimethylammonium chloride) (poly-DADMAC)/nylon-11 composite nanofibrous mat as a highly positive triboelectric layer to boost TENG performance. Incorporating cationic poly-DADMAC enhances the dielectric constant and surface charge trapping capability, leading to significantly improved output performance and mechanical strength.

Nano Energy
2021
Journal Article

Highly Responsive and Robust Micro-/Nano-Textured Self-Powered Triboelectric Humidity Sensor

MS Rasel, Pukar Maharjan, MT Rahman, Md Salauddin, SMS Rana, Sanghyun Lee, Jae Yeong Park

To overcome the reliance on external power for humidity sensors, this work demonstrates a self-powered triboelectric humidity sensor (TEHS) based on contact electrification between hydrophobic micro-/nano-textured PDMS and nano-textured aluminum films. The sensor produces an electrical output related to the relative humidity level, with ultrafast response and relaxation times.

ACS Applied Electronic Materials
2021
Journal Article

Keystroke Dynamics Based Hybrid Nanogenerators For Biometric Authentication And Identification Using Artificial Intelligence

Pukar Maharjan, Kumar Shrestha, Trilochan Bhatta, Hyunok Cho, Chan I Park, Md Salauddin, Muhammad Toyabur Rahman, SM Sohel Rana, Sang Hyun Lee, Jae Yeong Park

This paper reports a new keystroke dynamics-based hybrid nanogenerator for biometric authentication and identification, integrated with artificial intelligence (AI). Keystroke dynamics provide behavioral information that can distinguish individuals based on their typing rhythms. The hybrid nanogenerators convert keystroke energy into electrical signals, which are used by an AI system for authentication.

Advanced Science
2021
Journal Article

Ultra-Robust And Broadband Rotary Hybridized Nanogenerator For Self-Sustained Smart-Farming Applications

Muhammad Toyabur Rahman, SM Sohel Rana, Pukar Maharjan, Md Salauddin, Trilochan Bhatta, Hyunok Cho, Chan I Park, Jae Yeong Park

This paper reports a contactless mode triggering-based ultra-robust rotary hybridized nanogenerator (CMTUr-HNG) for harvesting energy from wind and water flows. By implementing a soft magnetic-coupled triggering strategy, the hybrid nanogenerator shows high output performance over a broad range of rotational motions (50–1000 rpm) with excellent robustness. The device is designed for self-sustained smart-farming applications.

Nano Energy
2021
Journal Article

High-performance keyboard typing motion driven hybrid nanogenerator

Pukar Maharjan, Trilochan Bhatta, Chan I Park, Hyunok Cho, Kumar Shrestha, Sang H Park, Md Salauddin, Muhammad Toyabur Rahman, SM Sohel Rana, Jae Yeong Park

This paper proposes a high-performance electromagnetic-triboelectric hybrid nanogenerator for harvesting biomechanical energy from keyboard typing motion (KTMEH). By combining electromagnetic induction and triboelectric contact electrification, the KTMEH can scavenge mechanical energy from keystrokes and deliver significant power from a single typewriter key.

Nano Energy
2021
Journal Article

Electrospun PVDF-TrFE/MXene Nanofiber Mat-Based Triboelectric Nanogenerator For Smart Home Appliances

SM Sohel Rana, Muhammad Toyabur Rahman, Md Salauddin, Sudeep Sharma, Pukar Maharjan, Trilochan Bhatta, Hyunok Cho, Chan I Park, Jae Yeong Park

This paper reports an electrospun nanofiber-based TENG (EN-TENG) using a PVDF-TrFE/MXene nanocomposite with a superior dielectric constant and high surface charge density. The influence of dielectric properties on the output performance of the EN-TENG is investigated theoretically and experimentally, with applications demonstrated in smart home appliances.

ACS Applied Material & Interfaces
2020
Journal Article

High-Performance Triboelectric Nanogenerator Based On MXene Functionalized Polyvinylidene Fluoride Composite Nanofibers

Trilochan Bhatta, Pukar Maharjan, Hyunok Cho, Chan I Park, Sang Hyuk Yoon, Sudeep Sharma, Md Salauddin, Muhammad Toyabur Rahman, SM Sohel Rana, Jae Yeong Park

This work proposes electrospun MXene (Ti₃C₂Tₓ) functionalized Polyvinylidene fluoride (PVDF) composite nanofiber as a promising negative triboelectric layer for boosting TENG performance. Blending Ti₃C₂Tₓ nanosheets into the PVDF matrix improves the dielectric property and surface charge density, substantially enhancing the triboelectric performance.

Nano Energy
2020
Journal Article

A Novel MXene/Ecoflex Nanocomposite-Coated Fabric As A Highly Negative And Stable Friction Layer For High-Output Triboelectric Nanogenerators

Md Salauddin, SM Sohel Rana, Md Sharifuzzaman, Muhammad Toyabur Rahman, Chan I Park, Hyunok Cho, Pukar Maharjan, Trilochan Bhatta, Jae Yeong Park

This paper introduces a novel MXene/Ecoflex nanocomposite as a promising triboelectric material due to its highly negative properties and mechanical stability. A fabric-based waterproof TENG (FW-TENG) using this nanocomposite is designed to harvest energy from human motions and the natural environment (rain and wind).

Advanced Energy Materials
2018
Journal Article

Miniaturized Springless Hybrid Nanogenerator For Powering Portable And Wearable Electronic Devices From Human-Body-Induced Vibration

Md Salauddin, Muhammad Toyabur Rahman, Pukar Maharjan, MS Rasel, Jae Woo Kim, Hyunok Cho, Jae Yeong Park

This paper presents a newly designed springless hybridized nanogenerator (SHEMG-TENG) with non-resonant behavior, where the output power continuously increases with input frequency and amplitude. The device utilizes a dual-Halbach array and combines contact-separation and sliding-mode TENGs to achieve high power generation from low-frequency human-body-induced vibrations.

Nano Energy
2018
Journal Article

High Performance Human-Induced Vibration Driven Hybrid Energy Harvester For Powering Portable Electronics

Md Salauddin, Muhammad Toyabur Rahman, Pukar Maharjan, Jae Yeong Park

This work demonstrates a hybrid energy harvester that uses a dual Halbach magnet array combined with a magnetically floated electromagnetic–triboelectric design to convert human-induced motion into electrical energy. The design incorporates a Halbach magnet array, nanostructured PTFE, Al-nano-grass, and magnetic springs to achieve very high generated powers.

Nano Energy
2019
Journal Article

Natural Wind-Driven Ultra-Compact And Highly Efficient Hybridized Nanogenerator For Self-Sustained Wireless Environmental Monitoring System

Muhammad Toyabur Rahman, Md Salauddin, Pukar Maharjan, MS Rasel, Hyunok Cho, Jae Yeong Park

This paper reports an ultra-compact, highly efficient, miniaturized windmill hybridized nanogenerator (MW-HNG) based on three conversion mechanisms: TENG, PENG, and EMG. The 3D-printed, fully-enclosed structure is designed to harvest natural wind energy and is suitable for self-powered wireless environmental monitoring systems.

Nano Energy
2020
Journal Article

A Battery‐Less Arbitrary Motion Sensing System Using Magnetic Repulsion‐Based Self‐Powered Motion Sensors and Hybrid Nanogenerator

Trilochan Bhatta, Pukar Maharjan, Md Salauddin, MT Rahman, SMS Rana, Jae Yeong Park

This work introduces a battery-less arbitrary motion sensing system by integrating a magnetic repulsion-assisted self-powered motion sensor with a hybrid nanogenerator (MRSMS–HNG). The device detects motion parameters of a moving object in any direction and simultaneously converts low-frequency vibrations (<5 Hz) into electricity. The system uses repulsive forces between magnets to achieve self-powered sensing.

Advanced Functional Materials
2020
Journal Article

Flexible and robust dry electrodes based on electroconductive polymer spray-coated 3D porous graphene for long-term electrocardiogram signal monitoring system

Md Abu Zahed, PS Das, Pukar Maharjan, SC Barman, Md Sharifuzzaman, Sang Hyuk Yoon, Jae Y Park

This study developed highly flexible and conductive dry electrodes using a biocompatible polymer (PEDOT:PSS) loaded on mechanically robust laser-induced graphene (LIG). These electrodes are designed for long-term, comfortable electrocardiogram (ECG) signal monitoring with fewer motion artifacts compared to conventional wet electrodes.

Carbon
2020
Journal Article

Biomechanical Energy-Driven Hybridized Generator as a Universal Portable Power Source for Smart/Wearable Electronics

MT Rahman, SMS Rana, Md Salauddin, Pukar Maharjan, Trilochan Bhatta, Jae Yeong Park

The fast growth of smart electronics requires novel solutions to power them sustainably. This paper reports a novel elastic impact-based nonresonant hybridized generator (EINR-HG) to effectively harvest biomechanical energy from diverse human activities. It integrates a nonlinear electromagnetic generator with two contact-mode triboelectric nanogenerators to generate hybrid electrical output simultaneously.

Advanced Energy Materials
2019
Journal Article

Design and experimental analysis of a low-frequency resonant hybridized nanogenerator with a wide bandwidth and high output power density

Md Salauddin, RM Toyabur, Pukar Maharjan, MS Rasel, Hyunok Cho, Jae Yeong Park

This study presents the design and analysis of a low-frequency resonant hybridized nanogenerator (LFR-HN) with a wide bandwidth and high output power density. The device integrates an electromagnetic generator (EMG) using a Halbach magnet array and a triboelectric nanogenerator (TENG) with nanostructured surfaces to effectively scavenge energy from low-frequency ambient vibrations.

Nano Energy
2019
Journal Article

Hand clapping inspired integrated multilayer hybrid nanogenerator as a wearable and universal power source for portable electronics

MS Rasel, Pukar Maharjan, Jae Yeong Park

This paper reports a human skin-based wearable and hybrid triboelectric-piezoelectric nanogenerator (HTEPENG) for harvesting biomechanical energy from hand clapping. By integrating a polarized PVDF film between two nanopillar PDMS films, the hybrid nanogenerator produces two triboelectric outputs and one piezoelectric output simultaneously from a single clap.

Nano Energy
2019
Journal Article

A laser ablated graphene-based flexible self-powered pressure sensor for human gestures and finger pulse monitoring

PS Das, A Chhetry, Pukar Maharjan, M. Salauddin Rasel, Jae Yeong Park

This work establishes a reliable, eco-friendly, and low-cost fabrication scheme for a novel TENG-based pressure sensor (TEPS). The sensor is designed for self-powered human gesture detection and wearable healthcare applications. Unlike conventional methods, this approach avoids expensive, multi-step techniques, making it suitable for mass production.

Nano Research
2018
Journal Article

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

MS Rasel, Pukar Maharjan, Md Salauddin, MT Rahman, Hyunok Cho, Jae Woo Kim, Jae Yeong Park

This paper demonstrates a highly efficient approach for a TENG-based pressure sensor capable of detecting a wide range of pressures with record-high sensitivity. The work focuses on maximizing energy conversion efficiency by optimally tuning the internal impedance of the TENG. The sensor is based on double-sided tribological layers of micro-patterned PDMS and PDMS-CNT nanocomposites.

Nano Energy
2020
Journal Article

A Fully Functional Universal Self‐Chargeable Power Module for Portable/Wearable Electronics and Self‐Powered IoT Applications

Pukar Maharjan, Trilochan Bhatta, Hyunok Cho, Xue Hui, Chani Park, Sanghyuk Yoon, Md Salauddin, MT Rahman, SM Sohel Rana, Jae Y Park

This paper presents a universal self-chargeable power module (USPM) that can efficiently harvest energy from various sources like human bio-mechanics, ocean waves, and automobile vibrations. It uses a multiple spring-based design for high performance at low frequencies (≤6 Hz) and accelerations (≤1 g). The USPM is a compact device with integrated power management and storage, providing a direct current power of up to 34.11 mW.

Advanced Energy Materials
2020
Journal Article

A human skin-inspired self-powered flex sensor with thermally embossed microstructured triboelectric layers for sign language interpretation

Pukar Maharjan, Trilochan Bhatta, Md Salauddin, MS Rasel, MT Rahman, SMS Rana, Jae Yeong Park

This work presents a highly sensitive, self-powered triboelectric flex sensor (STFS) inspired by the human skin's dermis-epidermis structure. The sensor, fabricated using a facile thermal embossing technique, can efficiently detect finger bending and hand gestures. It is designed for applications in human-machine interfaces, such as real-time sign language interpretation.

Nano Energy
2020
Journal Article

A highly miniaturized freestanding kinetic-impact-based non-resonant hybridized electromagnetic-triboelectric nanogenerator for human induced vibrations harvesting

MT Rahman, SMS Rana, Md Salauddin, Pukar Maharjan, Trilochan Bhatta, Hyunsik Kim, Hyunok Cho, Jae Yeong Park

This paper presents a highly miniaturized freestanding kinetic-impact-based hybridized nanogenerator (MFKI-HNG) to effectively harvest human-induced vibrations. It integrates an electromagnetic generator (EMG) and a freestanding-mode triboelectric nanogenerator (TENG) to generate hybridized outputs from the same mechanical load. A non-resonant mechanical system improves performance in the low-frequency range (≤5 Hz).

Applied Energy
2019
Journal Article

A human-machine interactive hybridized biomechanical nanogenerator as a self-sustainable power source for multifunctional smart electronics applications

SMS Rana, MT Rahman, M Salauddin, Pukar Maharjan, T Bhatta, Hyunok Cho, Jae Yeong Park

This paper reports a human–machine interactive hybridized biomechanical nanogenerator (HMI-HBNG) that includes an electromagnetic generator (EMG) with a Halbach magnet array and an interdigitated electrode-based triboelectric nanogenerator (TENG). The design enhances power output for applications in multifunctional smart electronics, with the Halbach array increasing EMG power eightfold.

Nano Energy
2018
Journal Article

An indoor power line based magnetic field energy harvester for self-powered wireless sensors in smart home applications

Pukar Maharjan, Md Salauddin, Hyunok Cho, Jae Yeong Park

In smart home systems, various IoT sensors are used for monitoring. However, these sensors depend on batteries. Herein, we present an indoor power line based magnetic field energy harvester (IPLEH) as a sustainable power supply for self-powered wireless monitoring sensors. The IPLEH harvests energy from the magnetic field of a current-carrying conductor without electrical contact, using a ferrite split-core that can be easily installed on existing power lines.

Applied Energy
2019
Journal Article

High-Performance Cycloid Inspired Wearable Electromagnetic Energy Harvester For Scavenging Human Motion Energy

Pukar Maharjan, Trilochan Bhatta, M.Salauddin Rasel, Md.Salauddin, M.Toyabur Rahman, Jae Yeong Park

Eco-friendly and wearable power sources are in high demand because of the hasty growth in smart wearable electronic devices including health care monitoring sensors. Here, we successfully designed and fabricated a high-performance cycloid-inspired wearable electromagnetic energy harvester (CEEH) for scavenging low frequency (≤5 Hz) human motion energy. The proposed CEEH introduces a cycloid curved structure as an energy harvester for the first time which provides the fastest descent for the freely rolling spherical magnet in the curve path, resulting an increment in the rate of cutting magnetic flux.

Applied Energy
2018
Journal Article

A human locomotion inspired hybrid nanogenerator for wrist-wearable electronic device and sensor applications

Pukar Maharjan, R. M. Toyabur, Jae Yeong Park

To reduce battery dependency in wearable IoT devices, this work demonstrates a novel curve-shaped wearable hybridized electromagnetic-triboelectric nanogenerator (WHEM-TENG). This fully-enclosed, light-weight harvester is driven by low-frequency human motion, incorporating the arm's swinging behavior and a freestanding rolling magnetic ball. The device was fabricated using cost-effective 3D-printing.

Nano Energy
2018
Journal Article

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

Pukar Maharjan, Hyunok Cho, M. Salauddin Rasel, Md. Salauddin, Jae Yeong Park

This work presents a fully-enclosed wrist-wearable hybridized electromagnetic-triboelectric nanogenerator (FEHN) for scavenging energy from low-frequency human wrist-motion (≤ 5 Hz). The FEHN utilizes a freely moving magnetic ball inside a circular tube to combine rolling electrostatic induction and electromagnetic induction. A flexible flux concentrator is used to enhance the electromagnetic output.

Nano Energy
2020
Conference Paper

A Highly Sensitive Self-Powered Flex Sensor for Prosthetic Arm and Interpreting Gesticulation

Pukar Maharjan, T. Bhatta, H. Cho, Jae Yeong Park

This paper presents a highly sensitive, self-powered triboelectric flex sensor designed for advanced applications such as prosthetic arm control and interpreting gesticulation. The sensor can efficiently detect finger bending motions and monitor hand gestures without needing an external power supply, paving the way for more intuitive human-machine interfaces.

2020 IEEE MEMS Conference
2019
Conference Paper

A fully-enclosed wrist-wearable hybrid nanogenerator for self-powered sensors

P Maharjan, J Y Park

This paper presents a fully-enclosed wrist-wearable hybridized electromagnetic-triboelectric nanogenerator (FE-HNG) for scavenging energy from the low-frequency human wrist motion (≤ 5 Hz). The FE-HNG incorporates the rolling electrostatic induction and electromagnetic induction using a freely moving magnetic ball inside a hollow circular tube. A thin flexible flux concentrating material is introduced to increase the emf and enhances the electromagnetic output performance.

Journal of Physics: Conference Series
2019
Conference Paper

Thermal Imprinted Self-Powered Triboelectric Flexible Sensor for Sign Language Translation

Pukar Maharjan, T. Bhatta, Jae Yeong Park

This paper presents a self-powered, flexible, and highly sensitive triboelectric sensor designed for sign language translation. The sensor is fabricated using a simple, cost-effective, and scalable thermal imprinting technique to create micro-structured triboelectric layers. This method, inspired by the dermis-epidermis interlocking in human skin, enhances the sensor's performance, enabling it to efficiently detect finger gestures and interpret sign language in real-time.

2019 20th International Conference on Solid-State Sensors, Actuators and Microsystems & Eurosensors XXXIII (TRANSDUCERS & EUROSENSORS XXXIII)
2018
Conference Paper

A human locomotion driven hybrid energy harvester for wrist wearable applications

P Maharjan, J W Kim, J Y Kim, J Y Park

This paper presents a hybrid energy harvester combining an electromagnetic generator (EMG) and a triboelectric nanogenerator (TENG) to scavenge energy from human locomotion. The device is designed for wrist-wearable applications, aiming to provide a sustainable power source for portable electronics by converting the mechanical energy of human motion into electricity.

Journal of Physics: Conference Series