scholarly journals In-Ear Energy Harvesting: Source Characterization and Mechanical Simulator (Part I)

2021 ◽  
Vol 4 (1) ◽  
pp. 36
Author(s):  
Michel Demuynck ◽  
Aidin Delnavaz ◽  
Jérémie Voix ◽  
Tigran Avetissian ◽  
Adrien Badel ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Mechanical Action ◽  
Global Dynamics ◽  
Source Characterization ◽  
Maximum Displacement ◽  
Test Fixture ◽  
Joint Activities ◽  
Jaw Joint ◽  
Power Capability ◽  
Promising Source

During daily activities, such as chewing, eating, speaking, and so forth, the human jaw moves, and the earcanal is deformed by its anatomic neighbor called the temporomandibular joint (TMJ). Given the frequency of those jaw joint activities, the earcanal dynamic movement is a promising source of energy in close proximity to the ear, and such energy can be harvested by using a mechanical–electrical transducer dubbed energy harvester. However, the optimal design of such micromachine requires the characterization of the TMJ’s range of motion, its mechanical action on the earcanal, and its mechanical power capability. For that purpose, this research presents two methods for analyzing the earcanal dynamic movements: first, an in situ approach based on the measurement of the pressure variation in a water-filled earplug fitted inside the ear canal, and second, an anatomic-driven mechanism in the form of a chewing test fixture capable of reproducing the TMJ kinematics with great precision. The pressure earplug system provides the earcanal global dynamics, which can be derived as an equivalent displaced volume, while the chewing test fixture provides the discrete displacement along the earcanal wall. Both approaches are complementary and contribute to a better analysis of the interaction between the TMJ and earcanal. Ultimately, knowledge of the maximum displacement area and the derived generated power within the earcanal will lead to the design of a micromachine, allowing for the further investigation of in-ear energy harvesting strategies.

Material Characterization and Mid-Span Bending Capacity With Finite Element Simulated Predictions

2011 ◽  
Author(s):  
Walter Anderson ◽  
Ahmadreza Eshghinejad ◽  
Mohammad Elahinia
Keyword(s):  
Finite Element ◽  
Load Capacity ◽  
Tensile Tests ◽  
Unified Model ◽  
Radius Of Curvature ◽  
Maximum Displacement ◽  
Test Fixture ◽  
Different Temperatures ◽  
Bending Capacity ◽  
Force Displacement

Intelligent materials have been the subject of research for many years. Shape memory alloys (SMAs) are a type of intelligent material that has been targeted for many different uses; such as actuators, sensors and structural supports. SMAs are attractive as actuators due to their large energy density. Although a great deal of information is available on the axial load capacity and on the tip force for SMA tweezer-like devices, there is not enough information about the load capacity at mid-span, especially at the macro-level. Imposed displacement at mid-span experimental evaluation of an SMA beam in the austenitic and martensitic regimes has been studied. To this end, a specimen of near equi-atomic nitinol was heat-treated (shape set) into a ‘U’ shape and loaded into a custom test fixture such that the boundary conditions of the beam are approximated as roller-roller; and the sample was deformed at different temperatures while reaction forces were measured. The displacement is near maximum displacement of the U shape without causing a change in concavity, thus full-scale capacity is shown. Additionally, Unified Model (finite element) predictions of the experimental response are also presented, with good agreement. Due to the robust nature of the Unified Model, geometric parameter variations (wire diameter and radius of curvature) were then simulated to encompass the design envelop for such an actuator. The material properties needed as inputs to the Unified Model were obtained from constant temperature tensile tests of a specimen subjected to the same heat treatment (shape set straight). The resultant critical stresses were then extracted using the tangent method similar to the one described in ASTM F-2082. It is worth noting that the specimen was trained before the stress value extraction, but the transversely loaded specimen was not trained due to the difficulty involved (inherent uneven stress distribution). The contribution of this work is the presentation of experimental results for transverse (mid-span) loading of a nitinol wire and the simulation results allowing for design of a proper actuator with known constraints on force, displacement or temperature (2 of 3 needed). In other words, this work could be used as a type of 3D look-up table; e.g. for a desired force/displacement, the required temperatures are given. Future work includes developing a sensor-less control strategy for simultaneous force/displacement control.

A Study on Bandwidth and Performance Limitations of Array Vibration Harvester Configurations

2019 ◽  
Vol 4 (1) ◽  
pp. 47-56 ◽  
Author(s):  
Noha Aboulfotoh ◽  
Jens Twiefel
Keyword(s):  
Energy Harvesting ◽  
Lower Limit ◽  
Output Power ◽  
Theoretical Study ◽  
Design Guidelines ◽  
Single Element ◽  
Upper Limit ◽  
Resonance Frequencies ◽  
And Performance ◽  
Power Capability

Abstract Many researchers introduced an array of generators for broadband energy harvesting. The array has been studied in comparison to a single element from this array, but never compared to a single reference harvester with same volume as the whole array. This paper presents a theoretical study of evaluating the performance of the array harvester in comparison to the reference harvester. Power from the reference harvester as well as from the array is analytically calculated. The array is compared to the reference harvester when loaded by their optimal resistances which provide maximum power capability. The comparison is divided into two sections: firstly when the elements of the array are tuned to resonate at matching frequencies and secondly when they are tuned to non-matching resonance frequencies. The comparisons lead to two significant limits of the working bandwidth of the array: the lower and the upper limit. Between the two limits, the power produced from the array is less than the reference harvester, but with a small additional bandwidth. Below the lower limit, the array has no advantage over the reference harvester. Above the upper limit, output power of the array is inconsistent. Hence, design guidelines for the array are provided.

scholarly journals In-Ear Energy Harvesting: Evaluation of the Power Capability of the Temporomandibular Joint

2020 ◽  
Vol 20 (12) ◽  
pp. 6338-6345 ◽  
Author(s):  
Jacob Bouchard-Roy ◽  
Aidin Delnavaz ◽  
Jeremie Voix
Keyword(s):  
Energy Harvesting ◽  
Temporomandibular Joint ◽  
Power Capability

scholarly journals In-Ear Energy Harvesting: Harvester Design and Validation (Part II)

2021 ◽  
Vol 4 (1) ◽  
pp. 43
Author(s):  
Tigran Avetissian ◽  
Fabien Formosa ◽  
Adrien Badel ◽  
Michel Demuynck ◽  
Aidin Delnavaz ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Hearing Aids ◽  
Mechanical Energy ◽  
Morphological Variability ◽  
Electric Energy ◽  
Low Frequency ◽  
Joint Movement ◽  
Ear Canal ◽  
Human Ear ◽  
Promising Source

The mechanical deformation of the ear canal induced by the temporomandibular joint movement constitutes a promising source of energy to power in-ear devices (hearing aids, communication earpieces, etc.). The large morphological variability of the human ear canal and its intrinsic dynamic characteristics—with displacement frequencies below 1.5 Hz with an average volume variation of 60 mm3—motivate the development of non-conventional dedicated energy harvesting methods. This paper demonstrates the concept and design of a modular hydraulic–piezoelectric self-actuated frequency up-conversion micromachine for energy harvesting. The mechanical energy is conveyed using a liquid-filled custom fitted earplug, which can be considered as a hydraulic pump. A hydraulic circuit composed of a pressure amplifier, two driven valves and two check valves allows to drive two micro-pistons. These micro-pistons actuate a bistable oscillator associated to a piezoelectric transducer allowing the low frequency mechanical excitation to be efficiently converted into electric energy through frequency-up conversion. The two integrated passively driven valves are based on tube buckling and allow the pistons to act alternatively on the oscillator to generate a backward and forward run for two jaw movements. A complete theoretical multiphysics model of the machine has been established for the design and evaluation of the potential of the proposed approach. Global analytical and refined FEM approaches have been combined to integrate the fluid and mechanical behaviors. Based on simulation and preliminary experimental data, the harvested energy is expected to be 8 µJ for one jaw closing, with a theoretical 40% end-to-end conversion efficiency.

Selective Ion Transport through Three-Dimensionally Interconnected Nanopores of Quaternized Block Copolymer Membranes for Energy Harvesting Application

Soft Matter ◽  
2021 ◽  
Author(s):  
Ja Min Koo ◽  
Chul Ho Park ◽  
Seungmin Yoo ◽  
Gyeong Won Lee ◽  
Seung Yun Yang ◽  
...  
Keyword(s):  
Block Copolymer ◽  
Energy Harvesting ◽  
Ion Exchange ◽  
Ion Transport ◽  
Concentration Gradient ◽  
Polymer Membranes ◽  
Electrical Energy ◽  
Energy Harvesters ◽  
Gradient Energy ◽  
Promising Source

The concentration gradient in aqueous solutions is a promising source of energy that can be harvested into electrical energy by ion-exchange polymer membranes. In concentration-gradient energy harvesters, ion transport through...

scholarly journals Design and Implementation of Wearable Microstrip Fabric Antenna for RF Energy Harvesting

2021 ◽  
Author(s):  
T. Rubesh kumar ◽  
Moorthi Madhavan
Keyword(s):  
Energy Harvesting ◽  
Base Station ◽  
Radiation Efficiency ◽  
Antenna Design ◽  
Wave Band ◽  
Wide Bandwidth ◽  
Rf Energy Harvesting ◽  
Dielectric Characterization ◽  
Rf Energy ◽  
Promising Source

Abstract In 5G network, the key parts are millimeter wave band (mmWave band) involving 26 GHz & 28 GHz which aims to solve issues related to traffic using its wide bandwidth. Features of 5G such as transmitters with high directivity, wide bandwidth and base station with high density project it as a promising source of RF energy harvesting. In order to harvest RF power from the full spectrum in an efficient way, broadband antenna design is demanded. This paper focuses on designing wearable microstrip fabric antenna operating in 5G spectrum at 26 GHz & 28 GHz for RF energy harvesting. Impedance bandwidth of the antenna is about 20 GHz to 30 GHz exhibiting omnidirectional pattern of radiation with on-body gain with a peak value of 7 dB making it suitable for harvesting RF energy. On body radiation efficiency & off body radiation efficiency are obtained as 40% and 60% when operating in the frequency range of 24 GHz & 30 GHz. In mmWave band, dielectric characterization of a two line fabric substrate microstrip antenna is obtained. Fabrication of the antenna is done using polyimide copper laminates etched with ultra thin size 150 µm on a woven polyester substrate of 310 µm thickness. Improved gain and stable bandwidth are achieved from the proposed antenna design when demonstrated in human proximity providing high robustness.

scholarly journals Conceptional Designs of the Rotation Mechanism with Antiphase Energy Harvester

2021 ◽  
Vol 10 (1) ◽  
pp. 30
Author(s):  
Xinyi Wang ◽  
Wensong Hu ◽  
Jingxian Xu ◽  
Chung Ket Thein
Keyword(s):  
Energy Harvesting ◽  
Vibration Amplitude ◽  
Permanent Magnets ◽  
Energy Harvester ◽  
Renewable Energy Sources ◽  
Maintenance Cost ◽  
Vibration Energy ◽  
Magnetic Flux Density ◽  
Vibration Energy Harvesting ◽  
Promising Source

Due to the increased demand for a sustainable source of energy, the research on energy harvesting has increased in the last twenty years. Energy harvesting aims to gain energy from the ambient environment and convert this energy into electrical power. There are different kinds of renewable energy sources and vibration energy harvesting (VEH) is the most promising source owing to its low maintenance cost. This paper focuses on an electromagnetic vibration energy harvester based on the concept of rotational energy harvesting. The proposed device uses a rotating rotor with permanent magnets and moves the repulsive magnet block up and down. The block is connected to an antiphase harvester, which creates power by cutting the magnetic flux density. The antiphase was proven to double the voltage when the antiphase was moving. To improve the vibration amplitude of the magnet block and the antiphase, springs were added to the proposed design. In the concept, four configurations—with and without different spring positions—were proposed. The experimental results showed that when the spring was placed in the upper and bottom part of the moving part, the spring at the bottom would generate the largest vibration amplitude. Based on Faraday’s Law of Induction, voltage is proportional to the velocity or vibration amplitude. Hence, for both cases, at least six times the voltage was generated compared to the design without added springs.

A Compact Multi-Input Power Conversion System with High Time-Efficiency Inductor–Sharing Technique for Thermoelectric Energy Harvesting Applications

2015 ◽  
Vol 25 (01) ◽  
pp. 1640007 ◽  
Author(s):  
Chia-Lun Chang ◽  
Tai-Cheng Lee
Keyword(s):  
Energy Harvesting ◽  
Output Power ◽  
Power Conversion ◽  
Maximum Output Power ◽  
Maximum Output ◽  
Power Extraction ◽  
Thermoelectric Energy ◽  
Thermoelectric Energy Harvesting ◽  
Energy Harvesting System ◽  
Power Capability

A compact multi-input thermoelectric energy harvesting system implemented in a 0.18[Formula: see text][Formula: see text]m CMOS technology is proposed to extract electrical energy from human body heat. By combining the techniques on inductor sharing and bidirectional power converter, the harvesting- and regulating-stage circuits in conventional energy harvesting system can be merged into a single-stage circuit. With the proposed duty-cycle-based strategy for maximum power extraction and the high-efficiency timing scheme for inductor sharing, the proposed multi-input thermoelectric energy harvesting system can ensure optimal power transfer from each thermoelectric energy source without sacrificing power conversion efficiency (PCE) and maximum output power capability. The peak PCE is achieved at 58.5%, the maximum end-to-end output power is 2.43[Formula: see text]mW, and the maximum output power capability is 32.4[Formula: see text]mW while the storage capacitor is fully charged.

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