USING PVDF FILMS AS FLEXIBLE PIEZOELECTRIC GENERATORS FOR BIOMECHANICAL ENERGY HARVESTING

In this paper, a commercial polymeric piezoelectric film, the polyvinylidene fluoride (PVDF) was used to harvest electrical energy during the execution of five locomotion activities (walking, going down and up the stairs, jogging and running). The PVDF film transducer was placed into a tight suit in proximity of four body joints (shoulder, elbow, knee and ankle). The RMS values of the power output measured during the five activities were in the range 0.1 – 10 µW depending on the position of the film transducer on the body. This amount of electrical power allows increasing the operation time of wearable systems, and it may be used to prolong the monitoring of human vital signals for personalized health, wellness, and safety applications

Energy harvesting from knee motion using piezoelectric patch transducers

This paper presents a piezoelectric energy harvesting device that generates electrical power from knee motion during human gait. The device is composed of two MEMS-based piezoelectric patch transducers optimized for placement around knee joints with minimal footprint. Simulations were performed on COMSOL software to reveal maximum performance that can be achieved under normal walking conditions. The internal capacitance of the patch transducers was measured to be 80 nF, while the resistance was on the order of 470 k. The patch transducers were inserted in a knee brace worn by a volunteer subject, and were characterized for voltage and power generation. During walking, the maximum open circuit voltage and rms power were measured to be 14 V and 6.2 uW, respectively. These values were observed to increase up to 14.4 V and 12 uW during a moderate running activity. The level of power achieved in the experiments shows the potential of this device as an independent onboard power component and as a continuous battery charger for wearable electronic devices.Bu çalışmada insanların yürüyüşleri esnasında diz hareketinden enerji elde edebilen bir piezoelektrik enerji hasadı aygıtının geliştirilmesi ve test edilmesi ele alınmıştır. Aygıt diz çevresine yerleştirmek üzere optimize edilmiş ve minimal ölçülere sahip iki adet MEMS tabanlı piezoelektrik yama dönüştürücüden oluşmaktadır. COMSOL programında yapılan simülasyonlar ile normal yürüme sırasında elde edilebilecek maksimum performans incelenmiştir. Piezoelektrik dönüştürücülerin iç kapasitans ve dirençlerinin 80 nF ile 470 kohm mertebesinde olduğu ölçülmüştür. Dönüştürücüler bir gönüllünün taktığı dizliğe yerleştirilerek, üretilen gerilim ve güç değerleri test edilmiştir. Yürüme sırasında maksimum 14 V ve 6.2 uW rms güç elde edilmiştir. Bu değerlerin orta hızlı koşma esnasında 14.4 V ve 12uW’a çıktığı gözlemlenmiştir. Ölçülen gerilim ve güç değerleri, bu aygıtın giyilebilir elektronik aletleri çalıştırabilme ve bu aletlerin pillerini sürekli şarj edebilme potansiyelini ortaya koymaktadır.No sponso

Preliminary Study of a Pendulum in Vivo Electromechanical Generator for Orthopedic Implants

This paper presents the principle and the energy potential of an original electromechanical generator that uses human body natural motions during walking, in order to create an autonomous generator. This in vivo and noninvasive system is intended to be used in intelligent knee prosthesis. As the combined human, mechanical, and electrical phenomena are very significant, a mechanical and an electrical study are then carried to evaluate the recoverable power

Study of a Pendulum in Vivo Electromechanical Generator to be Used in a Knee Prosthesis

International audienceThis paper presents the principle and the energy potential of an original electromechanical generator that uses human body natural motions during walking, in order to create an autonomous generator. This in vivo and noninvasive system is intended to be used in intelligent knee prosthesis. As the combined human, mechanical, and electrical phenomena are very significant, a mechanical and an electrical study are then carried to evaluate the recoverable power

Récupération d'Energie Biomécanique et Systèmes Autonomes

National audienceLa récupération d'énergie (Energy Harvesting) est une thématique en plein essor visant à utiliser l'énergie ambiante (lumière, vibrations, gradients thermiques) présente dans l'environnement direct de dispositifs électroniques (capteurs, équipements mobiles) pour les alimenter, de façon à prolonger leur durée de fonctionnement, voire à les rendre totalement autonomes. La récupération d'énergie est généralement mise en œuvre pour alimenter de petits systèmes électroniques tels que des capteurs autonomes communicants pour le transport, l'industrie ou l'habitat du fait des puissances récupérées assez faibles; appliquée au cas de l'Homme, la récupération d'énergie peut atteindre des puissances de plusieurs milliwatts voire de plusieurs watts permettant d'alimenter des systèmes plus complexes tels que des lecteurs MP3, des téléphones portables ou des systèmes de localisation GPS. De nombreuses sources d'énergie présentes dans l'environnement de l'Homme peuvent être exploitées: le soleil, le gradient thermique entre la peau et l'extérieur, la déformation des vêtements, les contraintes dans les chaussures... . Cet article se focalise plus particulièrement sur la récupération d'énergie mécanique issue du corps humain et présente des exemples de dispositifs et d'applications issus de l'état de l'art montrant que la récupération d'énergie est déjà une réalité; et qu'elle permettra sur le plus long terme d'alimenter des dispositifs placés directement à l'intérieur du corps humain tels que des implants médicaux ou des pacemakers

Mini-bâteau récupérateur de micro-énergie de vaguelette

This paper introduces an original research work on experimental demonstration of micro-energy harvesting from water wave. To implement this demonstrator, commercial piezo-electric elements are used as an electromechanical aquatic energy transducer. The proof-of-concept is constituted by electrical micro-energy sensor circuit implemented on a mini-boat external surface. The water wave is generated by the valve oscillating motion placed in a water tank. Because of the wave interaction with the piezo, it was shown that the electrical circuit placed on the micro-boat surface generates instantaneous electrical power with microwatt amplitude under some Volts amplitude instantaneous voltage. The influence of the boat orientation in function of the water wave propagation direction is investigated

Skin-touch-actuated textile-based triboelectric nanogenerator with black phosphorous for durable biomechanical energy harvesting

Textiles that are capable of harvesting biomechanical energy via triboelectric effects are of interest for self-powered wearable electronics. Fabrication of conformable and durable textiles with high triboelectric outputs remains challenging. Here we propose a washable skin-touch-actuated textile-based triboelectric nanogenerator for harvesting mechanical energy from both voluntary and involuntary body motions. Black phosphorus encapsulated with hydrophobic cellulose oleoyl ester nanoparticles serves as a synergetic electron-trapping coating, rendering a textile nanogenerator with long-term reliability and high triboelectricity regardless of various extreme deformations, severe washing, and extended environmental exposure. Considerably high output (~250–880 V, ~0.48–1.1 µA cm−2) can be attained upon touching by hand with a small force (~5 N) and low frequency (~4 Hz), which can power light-emitting diodes and a digital watch. This conformable all-textile-nanogenerator is incorporable onto cloths/skin to capture the low output of 60 V from subtle involuntary friction with skin, well suited for users’ motion or daily operations