Davide Alghisi

Battery-less non-contact temperature measurement system powered by energy harvesting from intentional human action

This paper presents a battery-less non-contact temperature measurement system powered by energy harvesting from intentional human action. The conversion between the human action and electrical energy is provided by a hand-crank electromagnetic (EM) converter. The AC voltage generated by the EM converter has time-varying amplitude and frequency and is rectified by a metal–oxide-semiconductor field-effect transistor-based voltage doubler active rectifier circuit. The harvested energy is efficiently stored into multiple capacitors by the innovative sequential charging of storage capacitors technique, and used to power a micro electro mechanical system thermopile sensor with related signal conditioning electronics plus a liquid-crystal display to visualise the temperature readings. With a force of about 29.4 N over 2 cm applied to the EM converter, the power management circuit is able to extract an energy of 27.5 mJ and power the non-contact temperature measurement system for about 33 s.

Portable battery-less noncontact temperature measurement system powered on-demand by human action

This paper presents an autonomous battery-less temperature measurement system powered on-demand by human action. The conversion between the human action and electrical energy is provided by an hand-held electromagnetic (EM) converter intentionally activated by the user. The AC voltage generated by the EM converter has time-varying amplitude and frequency and is rectified by a voltage doubler active rectifier circuit. The energy harvested is stored into multiple capacitors by the innovative Sequential Charging of Storage Capacitors (SCSC) technique. With a force of about 29.4 N over 2 cm applied to the EM converter, the power management circuit is able to extract an energy of 27.5 mJ and power the noncontact temperature measurement system for about 17 s.

Wireless noncontact temperature measurement system powered by intentional human action

In this paper, a wireless temperature measurement system powered by energy harvesting from human motion is presented. The user force exerted on the hand-crank ElectroMagnetic (EM) device is converted into electricity. The electrical energy is stored into multiple capacitors by the proposed active power management circuit with the Sequential Charging of the Storage Capacitors network (SCSC). With an applied force of about 29.4 N over 2 cm, 27.5 mJ of energy are stored and used to power the wireless temperature sensor module. The module performs a noncontact temperature measurement, shows the reading on an LCD display, and sends the temperature data over a wireless-UART link at 433 MHz to a host PC.

Portable Wireless Distance Measurement System Powered By Intentional Human Action

This work proposes and experimentally validates an handheld distance measurement system powered by energy harvesting through the ElectroMagnetic (EM) effect. The system is entirely battery-less and powered on-demand by the user force exerted on the lever of an hand-crack EM converter. With a single excitation force of about 19.6 N over a lever travel of 2 cm, the proposed system is able to perform a distance measurement between a target object and the embedded ultrasonic sensor, show the reading on a LCD display, and transmit the data through a 433-MHz wireless-UART link to an host PC.

Nonlinear Multi-frequency Converter Array for Energy Harvesting from Broadband Low-Frequency Vibrations

This work proposes and experimentally validates a vibration energy harvester which combines the multi-frequency and nonlinear approaches into a converter array. The converter array consists of four piezoelectric cantilevers composed of ferromagnetic substrates with screen-printed lead zirconate titanate (PZT) layers coupled with a single permanent magnet spring suspended on the array base in order to create a nonlinear behavior. The presence of the moving magnet and the possibility to fabricate cantilevers with different potential curves can be useful to obtain a collective nonlinear behavior due to strong coupling irrespective of the amplitude of the mechanical excitation, therefore increasing the overall effectiveness of the converter array. The experimental results confirm that combining cantilevers with different potential curves can be useful to obtain a collective bistable behavior, therefore increasing the overall effectiveness of the converter array.

Multi-frequency Nonlinear Converter Array for Energy Harvesting in Autonomous Sensors

In the present work a piezoelectric energy converter array from mechanical vibrations that combines the multi-frequency and nonlinear approaches is presented. Multiple piezoelectric cantilevers on ferromagnetic substrate with different frequency responses are combined in order to increase the overall equivalent bandwidth, while a permanent magnet introduces external nonlinear forces that create a bistable system capable to increase the tip velocity of cantilevers and the power converted, and shift the converter array bandwidth towards lower frequencies. The experimental results confirm that combining cantilevers with different potential curves can be useful to obtain a collective bistable behaviour, therefore increasing the overall effectiveness of the converter array.