Electromagnetic generator: As respiratory effort energy harvester

Abstract

Human power is one form of renewable energy that has shown to be promising to provide a solution for powering personal electronic devices when other energy sources are not readily available while reducing environmental waste associated with battery disposal and eliminating the need for battery displacement. This paper introduces a new paradigm of human energy harvesting with the ultimate goal of producing wearable zero-net energy biosensors by reusing the hardware components to perform both harvesting and sensing functions. The proposed energy harvesting method uses two miniature electromagnetic generators as the respiratory effort energy harvester, while at the same time the output voltage waveform of the system can be used to estimate the respiratory rate and depth. Preliminary simulation and experimental results indicate that sufficient energy can be obtained to power an ultra low power microcontroller with low data rate wireless link.

Energy Harvesting Electronic Systems

“…Some specific applications have also been documented, like in [42], where an electromagnetic generator is used both as a harvester and as a sensor, in a situation where the respiratory effort mechanical motion is the energy source. The harvested energy has been shown to be enough to continuously power a low-power microcontroller working with a low data rate wireless link, while monitoring the respiratory rate, and depth, of the user, with good accuracy.…”

Piezoelectric and electromagnetic respiratory effort energy harvesters

“…4 depicts the block diagram of a rotational electromagnetic energy harvester. An initial prototype for respiratory effort harvesting was tested in [16] while the output voltage (100mV) was not high enough for rectification purposes. Also, a low load resistance (10ohms) was used to provide high output current, while resulting in high required force for the armature to be turned [17].…”

“…One way to harvest power parasitically from breathing is using a chest belt including power scavenging modules [15][16][17]. Investigations show that the available harvestable power from circumferential change of the torso due to normal breathing without putting an onerous load on the user is on the order of mW [18].…”

“…In [15], the theoretical feasibility of using a piezoelectric bending generator to concurrently sense the respiratory effort and harvest energy was proposed. In [16], the idea of using a miniature DC generator as a harvester was simulated with a maximum output voltage of 0.1V and power of 2mW. An electromagnetic servomotor with a high gear ratio has been also been used [17] for the purpose of sensing and harvesting simultaneously, being able to produce higher voltage (0.7V) and power (15mW) with the trade-off of higher required force from the chest to move the motor armature.…”

Respiratory rate detection using a wearable electromagnetic generator

“…To power these systems, simple batteries and proximity radio frequency (RF) power scavenging [8] have been used. In [13,14], the concept of self-powered biosensors through sensing and harvesting methods for respiratory effort was introduced. In this paper we present experimental results demonstrating that the peak power of 15 mW can be harvested from the respiratory effort using a wearable off-the-shelf servo motor operating in reverse, while respiratory rate is extracted simultaneously with high accuracy.…”