Energy Harvesting ICs Research Articles

A Triboelectric Energy Harvesting IC With High-Voltage Synchronous Electric Charge Extraction Strategy and Superior Systematic Efficiency

A Triboelectric Energy Harvesting IC With High-Voltage Synchronous Electric Charge Extraction Strategy and Superior Systematic Efficiency

Self-Operating Flyback Converter for Boosting Ultra-Low Voltage of Thermoelectric Power Generator for IoT Applications

This article presents a novel self-operating flyback converter to boost the ultra-low voltage produced by thermoelectric power generator (TEG). The proposed converter uses dual transformer, one for low-voltage startup and other to extract power from TEG. The use of separate transformer provides high-voltage transfer ratio, reduces high series resistance loss, and brings down the input impedance of circuit. The copper wire wounds ferrite toroid core transformer provides very low series resistance and negligible core loss, which improves the circuit efficiency. This boost converter operates with an input voltage range of 22–300 mV and provides maximum output power of 0.073 – 147 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${\rm{mW}}$</tex-math></inline-formula> correspondingly. The peak efficiency of 68% with output power of 1.32 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${\rm{mW}}$</tex-math></inline-formula> (voltage ∼1.83 V) is achieved at an input voltage of 50 mV. For regulated output voltage, a feedback loop is used to keep output voltage constant during sudden voltage rise of TEG. The proposed circuit uses discrete components, ferrite toroid core, and PCB, which has lower cost than available energy harvester module, which uses energy harvesting ICs, discrete components, and tiny transformer. The lower startup voltage, higher output power, and voltage with high conversion efficiency of this boost converter maximize the applications potential of the TEG as a portable power source for Internet of Things (IoT) devices.

An Auto-Configurable Dual-Mode MPPT for Energy Harvesting With 12 nW–180 mW Conversion Range

This brief presents an energy harvester IC with the maximum power point tracking (MPPT) scheme for an ultra-wide input power range. In the energy harvester, the proposed auto-configurable dual-mode MPPT algorithm adaptively switches between a fixed charge search (FCS) mode and a fixed frequency search (FFS) mode, according to the input power level. The implemented chip in 180nm CMOS process achieves the widest input power range of 12nW-to-180mW with a peak efficiency of 93.6%, occupying <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.14\,\,{\times }\,\,1.24$ </tex-math></inline-formula> mm2. The proposed hill climbing-based MPPT scheme also shows a conversion efficiency of >30% even at 12nW input power while consuming a quiescent current of 2.2nA.

Application Of Energy Harvesting In The Field Of Mechanical Vibrations

Energy harvesting (EH) is the most upcoming technology which is defined as a process where the environmental energy sources such as load, mechanical vibrations, temperature changes, light energy, wind energy etc. are captured and transformed to acquire quite small levels of power within the of range of Nano Watts - Milliwatts. This method is used to power an installed system by accumulating energy from ambient sources such as solar, wind, thermal and radio frequency waves. It is also called Energy Scavenging. The purpose of energy harvesting is to power electronic devices where there are no conventional power sources. The energy harvesting device has design goals and the three main elements are energy Source, Energy harvesting IC, Energy storage. In particular the energy harvesting used in charging of rechargeable batteries on site, low power electronic devices like traditional and super capacitors. Common energy harvesting systems include a lot of applications in many remote locations, distant locations, undersea where batteries and conventional power are not in used practically. In this paper the research that has been carried away in the field of energy scavenging of vibration analysis was discussed. In this scenario different type of energy harvesting methods like Thermo electric harvesting, Piezo electric energy harvesting, Pyro electric Energy Harvesting, PVDF Films are studied and focused on the method which is relatively used to enhance the performance and transformation efficiency in the analysis of vibrations. From all the above methods the piezo electric energy harvesting is the one which is suitable for analysis of vibration since the deflection of a specimen using piezo electric material results in an electric displacement. This electricity can be used in storage of power in batteries or used to power portable devices.

Body-Area Powering With Human Body-Coupled Power Transmission and Energy Harvesting ICs.

This paper presents the body-coupled power transmission and ambient energy harvesting ICs. The ICs utilize human body-coupling to deliver power to the entire body, and at the same time, harvest energy from ambient EM waves coupled through the body. The ICs improve the recovered power level by adapting to the varying skin-electrode interface parasitic impedance at both the TX and RX. To maximize the power output from the TX, the dynamic impedance matching is performed amidst environment-induced variations. At the RX, the Detuned Impedance Booster (DIB) and the Bulk Adaptation Rectifier (BAR) are proposed to improve the power recovery and extend the power coverage further. In order to ensure the maximum power extraction despite the loading variations, the Dual-Mode Buck-Boost Converter (DM-BBC) is proposed. The ICs fabricated in 40 nm 1P8M CMOS recover up to 100 μW from the body-coupled power transmission and 2.5 μW from the ambient body-coupled energy harvesting. The ICs achieve the full-body area power delivery, with the power harvested from the ambiance via the body-coupling mechanism independent of placements on the body. Both approaches show power sustainability for wearable electronics all around the human body.

Low-cost, Implantable Wireless Sensor Platform for Neuromodulation Research.

The role of peripheral nerves in regulating major organ function in health and disease is not well understood. Elucidating the relationships between biomarkers and neural activity during conditions free form anesthesia is essential to advancing future investigations of autonomic organ control and improving precision for neuromodulation treatment approaches. Here we present a simple, customizable, off-the-shelf component sensor platform to meet research needs for studying different organs under conscious, free movement. The platform consists of a small, rechargeable coin-cell battery, an energy-harvesting IC, a low-power microcontroller, a low-power pressure transducer, customizable number of electrodes with a common anode, inductive recharge input, and OOK inductive transmission. A case study demonstrating a bladder implant for long-term monitoring is presented, utilizing a novel, non-hermetic encapsulation approach. The customized platform uses two sleep modes to minimize battery loading, exhibiting a maximum time-averaged current draw of 125 micro-amps during sensing and transmission, with a quiescent current draw of 95 nano-amps into the microcontroller.

Performance analysis of piezoelectric drum transducers as shoe-based energy harvesters

ABSTRACTPiezoelectric materials have been at the centre of energy harvesting research for a few decades now. This article explores the performance of piezoelectric drum transducers made using piezoelectric buzzer elements as shoe-based energy harvesters. Two sizes of drum transducers were fabricated, viz. 27 and 35 mm. Two different arrangements of these drums in stack as well as individual form were designed, embedded in shoes and tested with walk profile. Peak powers of 3.86 and 3.21 mW were obtained using a standard interface circuit whereas 1.23 and 0.38 mW using a MOSFET bridge with model 1 and 2, respectively. NiMH batteries of different capacities were charged using the shoe-based energy harvesters. An energy harvesting circuit using LTC 3588-1 energy harvesting IC was fabricated to obtain a regulated output voltage of 3.6 V using the shoe harvesters. Results show that these drum harvesters can be easily embedded in shoes and have the potential to act as excellent energy scavengers and generate enough power to drive low power sensors that can be used to design a smart body monitoring system.

A Single-Chip Solar Energy Harvesting IC Using Integrated Photodiodes for Biomedical Implant Applications.

In this paper, an ultra-compact single-chip solar energy harvesting IC using on-chip solar cell for biomedical implant applications is presented. By employing an on-chip charge pump with parallel connected photodiodes, a 3.5 × efficiency improvement can be achieved when compared with the conventional stacked photodiode approach to boost the harvested voltage while preserving a single-chip solution. A photodiode-assisted dual startup circuit (PDSC) is also proposed to improve the area efficiency and increase the startup speed by 77%. By employing an auxiliary charge pump (AQP) using zero threshold voltage (ZVT) devices in parallel with the main charge pump, a low startup voltage of 0.25 V is obtained while minimizing the reversion loss. A 4 Vin gate drive voltage is utilized to reduce the conduction loss. Systematic charge pump and solar cell area optimization is also introduced to improve the energy harvesting efficiency. The proposed system is implemented in a standard 0.18- [Formula: see text] CMOS technology and occupies an active area of 1.54 [Formula: see text]. Measurement results show that the on-chip charge pump can achieve a maximum efficiency of 67%. With an incident power of 1.22 [Formula: see text] from a halogen light source, the proposed energy harvesting IC can deliver an output power of 1.65 [Formula: see text] at 64% charge pump efficiency. The chip prototype is also verified using in-vitro experiment.

Synthesizable Integrated Circuit and System Design for Solar Chargers

In this paper, an automatic design tool for a solar energy harvesting IC and system is developed with visual basic software, and the synthesis tool employed in this approach can be used to shorten the design time to market. In addition, a smart meter system is developed to measure the solar energy harvesting system's information with an online system. Users can thus get the proposed system's information at any time and from anywhere. Finally, good agreement has been found between the analytic and experimental results.