An active piezoelectric energy extraction method for pressure energy harvesting

Abstract

This paper presents an energy harvesting technique to power autonomous systems and more particularly active implantable medical devices. We employ a piezoelectric diaphragm placed in a fluidic environment such as blood subjected to very low frequency (2 Hz) pressure variations that is deflected in a quasi-static manner and transduces mechanical energy into electrical energy. In order to maximize energy generation and to get the most out of a given piezoelectric device, we propose to apply an optimized method to extract the piezoelectrically generated charge through the application of a controlled voltage. We believe that this method could be one of the improvement levers to achieve self-powered miniaturized implants. An analytical model is presented and shows that within its validity domain, the extracted energy is proportional to the desired applied voltage. Taking power electronics losses into account can yield a theoretical increase in the extracted energy of several thousand per cent. Experimental measurements in a pressure chamber have been carried out whose results corroborate the proposed model. For the tested setup, the application of a 10 V peak amplitude square-wave voltage increased the extracted energy by a factor of nine compared to a classical rectifier-based energy harvesting method.

A multi-degree of freedom piezoelectric vibration energy harvester with piezoelectric elements inserted between two nearby oscillators

“…As a result, a number of approaches have been pursued to overcome this limitation. The approaches include multi-frequency Nomenclature u 0 the base excitation displacement u 1 the relative displacement of the 1st oscillator mass (m 1 ) with respect to the base u 2 the relative displacement of the 2nd oscillator mass (m 2 ) with respect to the base u n the relative displacement of the nth oscillator mass (m n ) with respect to the base m 1 the 1st oscillator mass m 2 the 2nd oscillator mass m n the nth oscillator mass k 1 the short circuit stiffness between the base and the oscillator (m 1 ) k 2 the short circuit stiffness between the m 1 and the m 2 k n the short circuit stiffness between the m n À 1 and the m n c 1 the short circuit mechanical damping between the base and the oscillator (m 1 ) c 2 the short circuit mechanical damping between the m 1 and the m 2 c n the short circuit mechanical damping between the m n À 1 and the m n C p1 the blocking capacity of the 1st piezoelectric patch element C p2 the blocking capacity of the 2nd piezoelectric patch element C pn the blocking capacity of the nth piezoelectric patch element R 1 the external resistance connected with 1st piezoelectric patch element R 2 the external resistance connected with 2nd piezoelectric patch element R n the external resistance connected with nth piezoelectric patch element α 1 the force factor of the 1st piezoelectric patch element α 2 the force factor of the 2nd piezoelectric patch element α n the force factor of the nth piezoelectric patch element V 1 the output voltage of the 1st piezoelectric patch element V 2 the output voltage of the 2nd piezoelectric patch element V n the output voltage of the nth piezoelectric patch element P 1 the harvested resonant power of the 1st piezoelectric patch element P 2 the harvested resonant power of the 2nd piezoelectric patch element P input the input power s the Laplace variable i the square root of À 1 η 1 the resonant energy harvesting efficiency of 1st piezoelectric patch element η 2 the resonant energy harvesting efficiency of 2nd piezoelectric patch element Superscripts U the first differential U U the second differential arrays [3][4][5], multi degrees of freedom energy harvester which is also known as multifunctional energy harvesting technology [6][7][8], passive and active self-resonant tuning technologies [9][10][11][12].…”

Enzymatic Glucose Biofuel Cell and its Application

“…The idea of harvesting energy directly from living organisms by building from a biological model, wherein the system is designed to utilize the internal chemical mechanisms (physiological activity) of a living organism to generate electrical power is considerably more stable and reliable than physical mechanisms (i.e., mechanical motion) [4,5]. Enzymatic glucose biofuel cells enable such energy harvesting via chemical mechanisms from blood metabolites such as glucose, wherein the electrodes modified with naturally occurring glucose and oxygen selective enzymes derived from micro-organisms are used to oxidize and reduce glucose and oxygen, respectively.…”

“…Previously researched biofuel cells employ DET, as well as employ MET [5,[30][31][32][33][34][35]. Direct electron transfer is generally achieved with enzyme with active center located in the peripheral area of the enzyme.…”

Implantable biofuel cells operating in vivo: Providing sustainable power for bioelectronic devices: From biofuel cells to cyborgs

“…Harvesting power from living species [21,22], including the human body [19,[23][24][25], using a broad variety of physical and chemical methods [19,26] has recently attracted significant attention. Physical methods of energy harvesting from living species often employ transducers utilizing mechanical energy [27]: muscle stretching [28], arm/leg swings [19], walking/running [19,29,30], heart beats [31,32], blood flow [26], gas flow due to respiration [19,31,33], etc.…”

“…Physical methods of energy harvesting from living species often employ transducers utilizing mechanical energy [27]: muscle stretching [28], arm/leg swings [19], walking/running [19,29,30], heart beats [31,32], blood flow [26], gas flow due to respiration [19,31,33], etc. Different thermoelectric [19], and piezoelectric [19] effects can also be used for the energy harvesting from a living body.…”