A vascular graft includes a flexible substrate that can assume an unrolled configuration, in which the substrate extends along a main extension plane, and a rolled-up configuration, in which a first side of the substrate is facing radially inward and a second sideof the substrate is facing radially outward. At least one pressure sensing device is arranged on the first side of the substrate and includes a first electrode, a second electrode, and a piezoelectric element arranged between the two electrodes. At least one velocity sensing device is arranged on the first side of the substrate and a first electrode, a second electrode, and a piezoelectric element arranged between the electrodes. The graft can be used in a vascular graft system.

A structure of an active mount is provided. The structure includes a case with an interior that is divided into upper and lower fluid chambers, a sealed hydro fluid flows based on a volume change of the upper fluid chamber due to deformation of an insulator, and flow characteristics of the hydro fluid are varied when power is applied to a driver. The structure further includes a generator that produces electricity based on behavior of the insulator. The generator is disposed within the case and the electricity produced by the generator is applied to the driver. Additionally, the generator autonomously produces electricity based on engine behavior and is mounted within an engine mount and, thus, supply of electricity from the outside is not required.

A self-powered sensing system is provided for the monitoring of quasi-static structural responses. The sensing system is comprised of: an energy concentrator having a member configured to detect a variation of a physical stimuli and change shape in response to the variation of the physical stimuli, where the variation typically occurs at a frequency less than one Hertz; a transducer coupled the member of the energy concentrator and generates a voltage in response to the change in shape of the member; and an event logging circuit configured to receive the voltage from the transducer and log the voltage in a non-volatile memory. Physical stimuli may include temperature, pressure or an applied force.

An energy harvester for converting vibration energy into electrical energy and harvesting the electrical energy includes: a base; a clamping structure which is supported by the base and is spaced apart from the base; an elastic member which is disposed between the base and the clamping structure and allows the clamping structure to be elastically moved relative to the base; and a cantilever structure including a cantilever beam having one side fixed to the clamping structure and the other side which is elastically bendable, and a mass body disposed on the cantilever beam.

Techniques for harvesting electrical energy from a plurality of harvesters is disclosed. An example energy harvesting system includes a plurality of harvesters and a signal conditioning circuit selectively coupled to an output of each of the plurality of harvesters. The system also includes an energy storage element coupled to the output of the signal conditioning circuit to be charged by the plurality of harvesters through the signal conditioning circuit. The system also includes a controller to discharge a selected harvester to the signal conditioning circuit when an output of the selected harvester triggers a charge collection.

The inventive concept discloses a piezoelectric energy harvesting array and a method of manufacturing the same. The manufacturing method may include forming a plurality of piezoelectric energy harvesting devices; connecting masses to one side of the piezoelectric energy harvesting devices and connecting the other side of the piezoelectric energy harvesting devices facing the masses to a base; and individually tuning a resonant frequency of each of the piezoelectric energy harvesting devices to prevent mismatch of resonant frequency when the masses vibrate.

A power generator including: a first vibration system in which a first mass member is elastically supported by a first spring member; and a second vibration system in which a second mass member is elastically supported by a second spring member, the first and second vibration systems providing a multiple-degree-of-freedom vibration system. A power generating element disposed between the first and second mass members is configured to convert vibration energy input to the first vibration system and the second vibration system from a vibrating member to electrical energy. A resonance frequency of the first vibration system is a frequency lower than 1/√2 times a frequency of a vibration input to the first vibration system from the vibrating member. A loss factor of the first spring member of the first vibration system is at least 0.01 but not greater than 0.2.

A vibrational energy harvesting system is disclosed. Included is a first energy harvesting unit and a second energy harvesting unit that convert mechanical vibrations into first and second AC signals, respectively. A first AC-DC converter coupled to the first energy harvesting unit and a second AC-DC converter coupled to the second energy harvesting unit are configured to convert the first AC signal and the second AC signal into a first DC signal and a second DC signal, respectively. A DC-DC converter is coupled between the second AC-DC converter and a controller, and is configured to receive the second DC signal and provide a regulated DC signal by using energy from the second DC signal in response to a periodic signal generated by the controller. Typically, an energy storage unit is coupled to the DC-DC converter and is configured to receive and store energy from the regulated DC signal.

A sensor device that senses proper acceleration. The sensor device includes a substrate, a spacer layer supported over a first surface of the substrate, at least a first tapered cantilever beam element having a base and a tip, the base attached to the spacer layer, and which is supported over and spaced from the substrate by the spacer layer. The at least first tapered cantilever beam element tapers in width from the base portion to the tip portion. The at least first cantilever beam element further including at least a first layer comprised of a piezoelectric material, a pair of electrically conductive layers disposed on opposing surfaces of the first layer, and a mass supported at the tip portion of the at least first tapered cantilever beam element.

This module comprises: a circuit for interfacing with the piezoelectric beam of an oscillating pendular unit, outputting a rectified signal comprising a sequence of pulses at a frequency equal to a multiple of the oscillation frequency of the pendular unit; a buffer capacitor charged by the successive pulses outputted by the interface circuit; and a converter regulator adapted to convert a capacitor discharge current into a stabilized power supply voltage, and controlled by a feedback control stage of the Maximum Power-Point Tracking (MPPT) type. A comparator detects the conduction of a blocking diode interposed between the interface circuit and the capacitor, in order to produce a signal representative of the current value of the duty cycle of the detected conduction and non-conduction periods. This signal is compared with a predetermined optimum duty cycle value in order to enable or disable the coupling of the capacitor to the converter regulator so as to control either the capacitor discharge towards an input of the converter regulator, or the continuation of its charging.