scholarly journals Double-Deck Metal Solenoids 3D Integrated in Silicon Wafer for Kinetic Energy Harvester

Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 74
Author(s):  
Nianying Wang ◽  
Ruofeng Han ◽  
Changnan Chen ◽  
Jiebin Gu ◽  
Xinxin Li

A silicon-chip based double-deck three-dimensional (3D) solenoidal electromagnetic (EM) kinetic energy harvester is developed to convert low-frequency (<100 Hz) vibrational energy into electricity with high efficiency. With wafer-level micro electro mechanical systems (MEMS) fabrication to form a metal casting mold and the following casting technique to rapidly (within minutes) fill molten ZnAl alloy into the pre-micromachined silicon mold, the 300-turn solenoid coils (150 turns for either inner solenoid or outer solenoid) are fabricated in silicon wafers for saw dicing into chips. A cylindrical permanent magnet is inserted into a pre-etched channel for sliding upon external vibration, which is surrounded by the solenoids. The size of the harvester chip is as small as 10.58 mm × 2.06 mm × 2.55 mm. The internal resistance of the solenoids is about 17.9 Ω. The maximum peak-to-peak voltage and average power output are measured as 120.4 mV and 43.7 μW. The EM energy harvester shows great improvement in power density, which is 786 μW/cm3 and the normalized power density is 98.3 μW/cm3/g. The EM energy harvester is verified by experiment to be able to generate electricity through various human body movements of walking, running and jumping. The wafer-level fabricated chip-style solenoidal EM harvesters are advantageous in uniform performance, small size and volume applications.

Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1730
Author(s):  
Ben Van Herbruggen ◽  
Jaron Fontaine ◽  
Anniek Eerdekens ◽  
Margot Deruyck ◽  
Wout Joseph ◽  
...  

To detect behavioral anomalies (disease/injuries), 24 h monitoring of horses each day is increasingly important. To this end, recent advances in machine learning have used accelerometer data to improve the efficiency of practice sessions and for early detection of health problems. However, current devices are limited in operational lifetime due to the need to manually replace batteries. To remedy this, we investigated the possibilities to power the wireless radio with a vibrational piezoelectric energy harvester at the leg (or in the hoof) of the horse, allowing perpetual monitoring devices. This paper reports the average power that can be delivered to the node by energy harvesting for four different natural gaits of the horse: stand, walking, trot and canter, based on an existing model for a velocity-damped resonant generator (VDRG). To this end, 33 accelerometer datasets were collected over 4.5 h from six horses during different activities. Based on these measurements, a vibrational energy harvester model was calculated that can provide up to 64.04 μW during the energetic canter gait, taking an energy conversion rate of 60% into account. Most energy is provided during canter in the forward direction of the horse. The downwards direction is less suitable for power harvesting. Additionally, different wireless technologies are considered to realize perpetual wireless data sensing. During horse training sessions, BLE allows continues data transmissions (one packet every 0.04 s during canter), whereas IEEE 802.15.4 and UWB technologies are better suited for continuous horse monitoring during less energetic states due to their lower sleep current.


Author(s):  
Jianyong Zuo ◽  
Jie Yu ◽  
Cheng Liu ◽  
Yihao Gu ◽  
Lei Zuo ◽  
...  

Abstract Railroad vibration energy harvester has been researched and developed to harness the energy from the vibration of railway track when the trains pass. The vibrational energy could be transformed into electrical energy using mechanical motion rectification (MMR) mechanism and then further be used to power trackside equipment including sensors and some smart electrical devices. In order to test the performance of the MMR railroad energy harvesting system, a series of infield tests were conducted with a self-developed distributed measurement system in Railroad Test Lab at Tongji University. A 10V peak voltage was achieved with 8 Ohms external resistive load at the train speed of 30 km/h, which was consistent with the result of in-lab bench tests. In addition, some experience of design and installation for the motioned based energy harvesting system was gained, which can provide some references for the future improvement of railroad energy harvesting systems.


Author(s):  
Valeria Nico ◽  
Elisabetta Boco ◽  
Ronan Frizzell ◽  
Jeff Punch

In recent years, the development of small and low power electronics has led to the deployment of Wireless Sensor Networks (WSNs) that are largely used in military and civil applications. Vibrational energy harvesting can be used to power these sensors in order to obviate the costs of battery replacement. Vibrational energy harvesters (VEHs) are devices that convert the kinetic energy present in the ambient into electrical energy using three principal transduction mechanisms: piezoelectric, electromagnetic or electrostatic. The investigation presented in this paper specifically aims to realize a device that converts vibrations from different ambient sources to electrical energy for powering autonomous wireless sensors. A “C-battery” scale (25.5 mm diameter by 57.45 mm long, 29.340 cm3) two Degree-of-Freedom (2-DoF) nonlinear electromagnetic energy harvester, which employs velocity amplification, is presented in this paper. Velocity amplification is achieved through sequential collisions between two free-moving masses, a primary (larger) and a secondary (smaller) mass. The nonlinearities are due to the use of multiple masses and the use of magnetic springs between the primary mass and the housing, and between the primary and secondary masses. Part A of this paper presents a detailed experimental characterization of the system dynamics, while Part B describes the design and verification of the magnet/coil interaction for optimum prototype power output. The harvester is characterized experimentally under sinusoidal excitation for different geometrical configurations and also under the excitation of an air-compressor. The maximum output power generated under sinusoidal excitation of arms = 0.4 g is 1.74 mW across a resistive load of 9975 Ω, while the output rms voltage is 4.2 V. Under the excitation of the compressor, the maximum peak power across a load resistance of 8660 Ω is 1.37 mW, while the average power is 85.5 μW.


Micromachines ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 701 ◽  
Author(s):  
Miah Abdul Halim ◽  
M. Humayun Kabir ◽  
Hyunok Cho ◽  
Jae Yeong Park

Energy harvesting from human-body-induced motion is mostly challenging due to the low-frequency, high-amplitude nature of the motion, which makes the use of conventional cantilevered spring-mass oscillators unrealizable. Frequency up-conversion by mechanical impact is an effective way to overcome the challenge. However, direct impact on the transducer element (especially, piezoelectric) increases the risk of damaging it and raises questions on the reliability of the energy harvester. In order to overcome this shortcoming, we proposed a transverse mechanical impact driven frequency up-converted hybrid energy harvester for human-limb motion. It utilizes the integration of both piezoelectric and electromagnetic transducers in a given size that allows more energy to be harvested from a single mechanical motion, which, in turn, further improves the power density. While excited by human-limb motion, a freely-movable non-magnetic sphere exerts transverse impact by periodically sliding over a seismic mass attached to a double-clamped piezoelectric bimorph beam. This allows the beam to vibrate at its resonant frequency and generates power by means of the piezoelectric effect. A magnet attached to the beam also takes part in generating power by inducing voltage in a coil adjacent to it. A mathematical model has been developed and experimentally corroborated. At a periodic limb-motion of 5.2 Hz, maximum 93 µW and 61 µW average powers (overall 8 µW·cm−3 average power density) were generated by the piezoelectric and the electromagnetic transducers, respectively. Moreover, the prototype successfully demonstrated the application of low-power electronics via suitable AC-DC converters.


Author(s):  
Yan Peng ◽  
Dong Zhang ◽  
Jun Luo ◽  
Shaorong Xie ◽  
Huayan Pu ◽  
...  

Abstract Recent years have witnessed explosive increase in the number of wearable devices in the market and industry. However, hardly have these devices gained the ability to capture energy from hosts and then get self-charged. In this paper, we design and build a novel wearable electromagnetic energy harvester to scavenge the kinetic energy of human ankle during walking or running. The design is composed of mainly three parts: a spring-mass system, rolling ball pair and the electromagnetic transduction mechanism. The harvester adopts an array of alternating south- and north-pole magnets. This arrangement allows the array exhibits a unique phenomenon, i.e. abrupt magnetic flux density changes within the array. Because of this phenomenon, the harvester displays excellent performance such as relatively high voltage and high power output. We then conducted FEM analysis to validate the hypothetical abrupt flux density changes. A prototype was fabricated for experimental studies. We investigated open-circuit voltage output, current output, and power as well as charging performance into energy storage components. The result shows that harvester possesses excellent performance with the maximum output voltage of 8.64V, peak-peak power of 700mW and the highest volume power density of 24.9mW/cm3. The energy harvester, as a renewable portable power source, can be of great significance for powering smart wearable electronic devices and health care monitoring sensors.


Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1545
Author(s):  
Xinyi Wang ◽  
Jiaxing Li ◽  
Chenyuan Zhou ◽  
Kai Tao ◽  
Dayong Qiao ◽  
...  

Most of the miniaturized electromagnetic vibrational energy harvesters (EVEHs) are based on oscillating proof mass suspended by several springs or a cantilever structure. Such structural feature limits the miniaturization of the device’s footprint. This paper presents an EVEH device based on a torsional vibrating magnet over a stack of flexible planar coils. The torsional movement of the magnet is enabled by microfabricated silicon torsional springs, which effectively reduce the footprint of the device. With a size of 1 cm × 1 cm × 1.08 cm, the proposed EVEH is capable of generating an open-circuit peak-to-peak voltage of 169 mV and a power of 6.9 μW, under a sinusoidal excitation of ±0.5 g (g = 9.8 m/s2) and frequency of 96 Hz. At elevated acceleration levels, the maximum peak-to-peak output voltage is 222 mV under the acceleration of 7 g (±3.5 g).


2020 ◽  
Vol 64 (1-4) ◽  
pp. 201-210
Author(s):  
Yoshikazu Tanaka ◽  
Satoru Odake ◽  
Jun Miyake ◽  
Hidemi Mutsuda ◽  
Atanas A. Popov ◽  
...  

Energy harvesting methods that use functional materials have attracted interest because they can take advantage of an abundant but underutilized energy source. Most vibration energy harvester designs operate most effectively around their resonant frequency. However, in practice, the frequency band for ambient vibrational energy is typically broad. The development of technologies for broadband energy harvesting is therefore desirable. The authors previously proposed an energy harvester, called a flexible piezoelectric device (FPED), that consists of a piezoelectric film (polyvinylidene difluoride) and a soft material, such as silicon rubber or polyethylene terephthalate. The authors also proposed a system based on FPEDs for broadband energy harvesting. The system consisted of cantilevered FPEDs, with each FPED connected via a spring. Simply supported FPEDs also have potential for broadband energy harvesting, and here, a theoretical evaluation method is proposed for such a system. Experiments are conducted to validate the derived model.


2017 ◽  
Vol 137 (6) ◽  
pp. 152-158
Author(s):  
Satoshi Inoue ◽  
Takuya Takahashi ◽  
Momoko Kumemura ◽  
Kazunori Ishibashi ◽  
Hiroyuki Fujita ◽  
...  

Author(s):  
E. L. Wolf

Protons in the Sun’s core are a dense plasma allowing fusion events where two protons initially join to produce a deuteron. Eventually this leads to alpha particles, the mass-four nucleus of helium, releasing kinetic energy. Schrodinger’s equation allows particles to penetrate classically forbidden Coulomb barriers with small but important probabilities. The approximation known as Wentzel–Kramers–Brillouin (WKB) is used by Gamow to predict the rate of proton–proton fusion in the Sun, shown to be in agreement with measurements. A simplified formula is given for the power density due to fusion in the plasma constituting the Sun’s core. The properties of atomic nuclei are briefly summarized.


Sign in / Sign up

Export Citation Format

Share Document