사용자 환경 모니터링을 위한 소형 자가발전 무선 데이터 송수신 시스템 개발

장순민 ( Sunmin Jang ),조수민 ( Sumin Cho ),정윤수 ( Yoonsu Joung ),김재형 ( Jaehyoung Kim ),김현수 ( Hyeonsu Kim ),장다연 ( Dayeon Jang ),라윤상 ( Yoonsang Ra ),이동한 ( Donghan Lee ),라문우 ( Moonwoo La ),최동휘 ( Dongwhi Choi ) 한국화학공학회 2022 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.60 No.2

With the rapid advance of the semiconductor and Information and communication technologies, remote environment monitoring technology, which can detect and analyze surrounding environmental conditions with various types of sensors and wireless communication technologies, is also drawing attention. However, since the conventional remote environmental monitoring systems require external power supplies, it causes time and space limitations on comfortable usage. In this study, we proposed the concept of the self-powered remote environmental monitoring system by supplying the power with the levitation-electromagnetic generator (L-EMG), which is rationally designed to effectively harvest biomechanical energy in consideration of the mechanical characteristics of biomechanical energy. In this regard, the proposed L-EMG is designed to effectively respond to the external vibration with the movable center magnet considering the mechanical characteristics of the biomechanical energy, such as relatively low-frequency and high amplitude of vibration. Hence the L-EMG based on the fragile force equilibrium can generate high-quality electrical energy to supply power. Additionally, the environmental detective sensor and wireless transmission module are composed of the micro control unit (MCU) to minimize the required power for electronic device operation by applying the sleep mode, resulting in the extension of operation time. Finally, in order to maximize user convenience, a mobile phone application was built to enable easy monitoring of the surrounding environment. Thus, the proposed concept not only verifies the possibility of establishing the self-powered remote environmental monitoring system using biomechanical energy but further suggests a design guideline.

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>

K-Pop 댄스 수준에 따른 근활성도 및 운동역학적 에너지 비교 분석

장영관,홍수연,김진현 한국스포츠학회 2016 한국스포츠학회지 Vol.14 No.1

The purpose of this study was to compare Biomechanical energy and muscle activation analysis of according to K-Pop dance level. Thirteen subjects(5 men, 8 women) who K-Pop dance professional choreographer were participated in this study. We divided 40 dance song 2 groups: level 1 (26.4±2.85kcal), level 2(49.65±5.53) based on of energy consumption. In order to measure muscle activity, the delsys (USA) was used. Seven muscles (biceps brachii, triceps brachii, rectus abdominis, rectus femoris, biceps femoris, tibialis anterior, gastrocnemius) activation were analyzed. As a result, Muscle Activity of all the segment does not affect the energy consumption. but, Depending on level, biceps femoris muscle activities were significantly different. Second, mechanical energy and energy consumption has an effect to each other. Third, Level 2 used more mechanical energy than the level 1. And according to level, potential energy, rotation energy and kinetic energy showed statistical different.

Extremely high and elongated power output from a mechanical mediator-assisted triboelectric nanogenerator driven by the biomechanical energy

Yoo, Jaewon,Yoo, Donghyeon,Lee, Seoulmin,Sim, Jae-Yoon,Hwang, Woonbong,Choi, Dongwhi,Kim, Dong Sung unknown 2019 Nano energy Vol.56 No.-

<P><B>Abstract</B></P> <P>The triboelectric nanogenerator (TENG) is considered as a promising auxiliary source of power for portable and wearable devices. However, the power output from previously suggested TENGs driven with biomechanical energy has been insufficient for practical applications. This study suggests the concept of a Mechanical Mediator-Assisted TENG (MMA-TENG). The proposed MMA-TENG is constructed by adding a mechanical mediator (MM), which is based on a novel mechanical gear mechanism that transforms the input motion into a more favorable form for generation, to an existing freestanding rotational TENG (FR-TENG). The addition of the MM makes the MMA-TENG capable of generating an extremely high and elongated power output despite the kinematic limitations of biomechanical movements (low velocity of ~10<SUP>0</SUP> m/s and low frequency of ~ 10<SUP>0</SUP> Hz). Driven with a single hand grip motion, the MMA-TENG can generate energy at a frequency of up to 2500 Hz and realize a strikingly high power output of up to 26 mW at an optimal matching impedance of 2 MΩ. Also, it continues to generate energy for an elongated duration of 7 extra seconds after the hand grip input motion is stopped, thereby harvesting 96 mJ of energy from 8000 cycles in total. This amount is over 1000 times of that harvested from the FR-TENG without the MM for the same input (0.084 mJ from 7 cycles). After the investigation into the output characteristics of the MMA-TENG, the principle by which such striking output characteristics are enabled with it is intensively studied through a detailed kinetic analysis. Finally, several proof-of-concept demonstrations with the MMA-TENG including a charging of a 100 μF capacitor with an extremely high charge transfer quantity of ~300 μC for a single hand grip input, and a real-time generation of 5 V DC output with a buck-boost circuit are shown. Such outstanding characteristics of the MMA-TENG are expected to greatly widen the applicability of TENGs as a potent and practical biomechanical energy harvester to aid the powering of portable and wearable electronic devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A mechanical way to increase power output of triboelectric nanogenerator is proposed. </LI> <LI> A rationally designed gear mechanism enables high and elongated power output. </LI> <LI> From hand grip, high generation frequency of 2500 Hz and power of 26 mW is achieved. </LI> <LI> From a single hand grip motion, the MMA-TENG transfers 300 µC of electrical charges. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Triboelectric Nanogenerators Based on Immobilized Living Microalgae for Biomechanical Energy Harvesting

Sugato Hajra,Pichaya In-na,Chalampol Janpum,Swati Panda,Hoe Joon Kim 대한금속·재료학회 2023 ELECTRONIC MATERIALS LETTERS Vol.19 No.4

Triboelectric nanogenerators (TENGs) are gaining attention for energy supply because of higher demands in decentralizedenergy production. TENGs are known for being self-energy harvesters, converting wasted mechanical energy to usefulelectrical energy under an ambient environment. Advantages of TENGs include a clean energy supply, a wide range ofmaterials selection, and an energy scavenging capability in the ambient environment. However, TENGs still suffer from theirlow electrical outputs compared to existing electrical supplies such as fuel cells and batteries. In bio-photovoltaic (BPV),there has been an interest in the use of microalgae, which are photosynthetic microorganisms capable of carbon capture andgenerating bioelectricity both day and night through electron transport chains via photosynthesis and cell respiration. Toincrease the current output of BPV, many have tried to immobilize living microalgal cells onto electrodes for higher masstransfers leading to higher photosynthetic rates. In this study, we have used immobilized living microalgae (Chlorella sp.)onto aluminium sheets to fabricate the TENG systems and investigate biomechanical energy harvesting. This proof of conceptshows that this integration of microalgae with TENG can enhance the voltage and current output achieved by the dualoperation modes of TENG. One issue raised during the tests was maintaining microalgae alive for several days, which hasgiven opportunities for further studies in nutrient and light supplies to this innovative sustainable hybrid technology. Theresults confirm that the microalgae can be an excellent triboelectric layer in TENG for biomechanical energy harvesting.

An Omnidirectional Biomechanical Energy Harvesting (OBEH) Sidewalk Block for a Self-Generative Power Grid in a Smart City

Jinshi Cui,윤헌준,윤병동 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.5 No.4

Energy harvesting, which converts ambient, otherwise wasted, energy sources into usable electricity, is expected to contribute to the formulation of a self-generating power grid. This type of grid can enable sustainable operation of wireless sensor networks as the “Smart City” vision becomes reality. Human walking is a plentiful mechanical energy source wasted during daily activities. This study aims to develop an omnidirectional biomechanical energy harvesting (OBEH) sidewalk block that is able to generate electricity from human walking. Here, a systematic design framework for the OBEH sidewalk block is presented; it consists of three important ingredients, specifically: (1) extraction of a footstep loading profile from human gait analysis; (2) electroelastically coupled finite element modeling to estimate the transient output responses under the footstep loading profile; and (3) reliability-based design optimization of the OBEH sidewalk block. This study considers two kinds of the inherent randomness, including (1) variability in the material properties and geometry; and (2) uncertainty in the position and direction of the footsteps. It can be concluded from the results that the optimum design of the proposed OBEH sidewalk block enables useful power generation while satisfying the target reliability of fatigue failure in the presence of the inherent randomness.

A durable and stable piezoelectric nanogenerator with nanocomposite nanofibers embedded in an elastomer under high loading for a self-powered sensor system

Siddiqui, Saqib,Kim, Do-Il,Roh, Eun,Duy, Le Thai,Trung, Tran Quang,Nguyen, Minh Triet,Lee, Nae-Eung Elsevier 2016 Nano energy Vol.30 No.-

<P><B>Abstract</B></P> <P>Practical usage of piezoelectric nanogenerators (PENGs) under heavy loading environments for high power generation, such as smart shoes, has been limited due to the low mechanical endurance of many piezoelectric materials. Durability and performance under harsh environments are a stumbling block for the practical application of PENGs. Synthesis of piezoelectrically enhanced nanofibers electrospun from nanocomposite of barium titanate nanoparticles (BT NPs) dispersed in poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) enables successful fabrication of a robust, efficient, flexible and lead-free PENG. A nanofiber PENG (nf-PENG) fabricated by embedding nanocomposite nanofibers in an elastomer film is demonstrated for biomechanical energy harvesting and storage during walking. When placed inside of a shoe, a nf-PENG loaded with 15wt% BT NPs can generate an output of 25V at a walking frequency of 0.6Hz with high mechanical durability under very high loads (600N). This can charge a 4.7µF capacitor after approximately 72 steps. The stored charge can operate a strain sensor without any external power supply. The high performance of the nf-PENG is mainly attributed to the self-poled nanocomposite nanofibers. Additionally, embedding the nanofibers into an elastomer provided high durability by protecting the nanofibers from mechanical damage. Furthermore, the devices small form factor, flexibility, and transparency make this nf-PENG suitable for applications in wearable electronics, where aesthetics and comfort are also desired (in addition to performance). This work demonstrates the possibility of highly durable, efficient, and self-powered wearable sensing systems that can work under extreme environments.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Lead-free piezoelectric nanocomposite nanofibers. </LI> <LI> High durability under harsh environments and high loadings. </LI> <LI> Harvesting and storing biomechanical energy during walking. </LI> <LI> Self-powered system. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>A highly durable, efficient and flexible piezoelectric nanogenerator, comprised of piezoelectric nanocomposite nanofibers embedded into an elastomer, was designed for energy harvesting under heavy loading conditions. The high resistance of the generator to ambient conditions for prolonged periods of time, as well as resistance to damage under heavy loading conditions, enabled the efficient harvest of bio-mechanical energy during human walking. This energy could be stored in a capacitor to create a self-powered sensor system. This approach may help enable practical applications of piezoelectric nanogenerators in wearable systems.</P> <P>[DISPLAY OMISSION]</P>

Biomechanical features of level walking by transtibial amputees wearing prosthetic feet with and without adaptive ankles

Chang-Yong Ko,Sol-Bi Kim,김종권,장윤희,조현석,김신기,류제청,문무성 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.6

This study aimed to evaluate the kinematics and kinetics of the lower limb in both the intact and amputated leg in individuals with transtibial amputations wearing Energy storage and return feet (ESRFs) with fixed ankles and Prosthetic feet with adaptive ankles (PFAAs) during level walking. Three individuals with transtibial amputations walked on level ground wearing their own ESRFs and PFAAs. Spatiotemporal parameters, kinematics, and kinetics of the lower-extremity joints were measured in the amputated and intact legs. There were differences in the kinematics of the joints in the amputated leg and of the ankle in the intact leg between ESRFs and PFAAs. Differences in joint moments, power, and stiffness in most joints in both legs and braking impulse were found between ESRFs and PFAAs. Thus, although it was a pilot study with three subjects, ankle angle control mechanisms (ESRFs: Fixed ankle vs. propriofoot: Mechanical motor vs. élan and echelon: Hydraulic actuator) might affect biomechanical features during level walking.

Design of the Energy Transmission System of Triboelectric Nanogenerator based on the Biomechanical Characteristics and Its Various Applications

S. Cho(조수민),S. Jang(장순민),Y. Ra(라윤상),M. La(라문우),S. J. Park(박성제),D. Choi(최동휘) Korean Society for Precision Engineering 2022 한국정밀공학회 학술발표대회 논문집 Vol.2022 No.5

Constitutive law of healthy gallbladder walls in passive state with damage effect

Wenguang Li 대한의용생체공학회 2019 Biomedical Engineering Letters (BMEL) Vol.9 No.2

Biomechanical properties of human gallbladder (GB) wall in passive state can be valuable to diagnosis of GB diseases. In the article, an approach for identifying damage eff ect in GB walls during uniaxial tensile test was proposed and a strainenergy function with the damage eff ect was devised as a constitutive law phenomenologically. Scalar damage variables wereintroduced respectively into the matrix and two families of fi bres to assess the damage degree in GB walls. The parametersin the constitutive law with the damage eff ect were determined with a custom MATLAB code based on two sets of existinguniaxial tensile test data on human and porcine GB walls in passive state. It turned out that the uniaxial tensile test datafor GB walls could not be fi tted properly by using the existing strain energy function without the damage eff ect, but couldbe done by means of the proposed strain energy function with the damage eff ect involved. The stresses and Young modulideveloped in two families of fi bres were more than thousands higher than the stresses and Young’s moduli in the matrix. According to the damage variables estimated, the damage eff ect occurred in two families of fi bres only. Once the damageoccurs, the value of the strain energy function will decrease. The proposed constitutive laws are meaningful for fi nite elementanalysis on human GB walls.