Electromagnetically transparent conductive materials, in particular nanomaterials, are used in a sensor along with piezoelectric materials to detect the motion of a subject to provide respiratory and cardiac gating for imaging techniques such as MRI, CT scans and PET.

Disclosed herein is a composition and a method for energy harvesting and the autonomous detection of structural failure. This method can be used to monitor, for example, the structural integrity of unmanned aircraft systems.

Provision of a piezoelectric element which uses a lightweight and flexible electret material and an electrode layer which is also lightweight, has high conductivity and good flexibility to easily receive electrical signals from an electret, and has good durability. Additionally, provision of a musical instrument provided with such a piezoelectric element. A piezoelectric element comprising an electrode layer (B) on at least one surface of an electret material (A) having pores inside, wherein a porosity of the electret material (A) is 20 to 80%, the electrode layer (B) contains 20 to 70 mass % of a carbon fine particle, and a thickness of the electrode layer (B) is 2 to 100 μm.

Aspects of the present disclosure describe systems, methods, and structures that scavenge mechanical energy to provide electrical energy to a wearable, where the mechanical energy is scavenged by a bending-strain-based transducer that includes a non-resonant energy harvester. By employing a non-resonant energy harvester that operates in bending mode, more electrical energy can be generated that possible with prior-art energy harvesters. In some embodiments the bending-strain-based transducer also includes a sensor and/or a haptic device. Some transducers in accordance with the present disclosure comprise a piezoelectric layer comprising a low-K piezoelectric material, such as aluminum nitride, which enables generation of higher voltage and power/energy output and/or a thinner transducer. As a result, transducers in accordance with the present disclosure can be included in wearables for which large transducer thickness would be problematic, such as shoe insoles, midsoles or outsoles, garments, bras, handbags, backpacks, and the like.

In some embodiments, the present invention is directed to an exemplary inventive method having steps of: providing at least one housing having a pre-determined physical structure; fixing a first edge of at least one electro-active polymer (EAP) film within the at least one housing; connecting a first edge of at least one pulling mechanism to a second edge of the at least one EAP film; where a second edge of the at least one pulling mechanism extends outside of the at least one housing; sufficiently pulling at the second edge of the at least one pulling mechanism to form at least one pre-stretched EAP film that has been stretched in a first axial direction within the at least one housing by a first pre-determined, pre-stretched amount; and where the pre-determined, pre-stretched amount is limited by the pre-determined physical structure of the housing.

An oral care device for placement in the oral cavity. The oral care device may include a support component, a piezoelectric component, and/or a therapeutic element. The support component is configured for placement between one or more maxillary teeth and one or more mandibular teeth. The piezoelectric element is configured to generate an electrical current from relative movement of the maxillary teeth and the mandibular teeth. The therapeutic element is configured to release a therapeutic composition into the oral cavity at least in part in response to receiving the electrical signal. The device may include the piezoelectric component, the therapeutic element, or both.

Provided is a novel piezoelectric element that has a generally long linear shape and has excellent flexibility and bend resistance. The piezoelectric element includes a core wire which is a resin wire having at least one layer of metal foil helically wound therearound, an organic piezoelectric layer that coats the core wire, and a conductor layer that coats the organic piezoelectric layer. The metal foil and the conductor layer each function as an electrode having the organic piezoelectric layer interposed therebetween. The at least one layer of metal foil is helically wound around the resin wire with gaps, and the ratio of the gap to the helical pitch of the metal foil is 0.4% to 50%.

Provided is: an elongated plate-form piezoelectric body, which contains an optically active helical chiral polymer (A) having a weight-average molecular weight of from 50,000 to 1,000,000 and has an elongated plate shape having a thickness of from 0.001 mm to 0.2 mm, a width of from 0.1 mm to 30 mm and a width-to-thickness ratio of 2 or higher, and in which the lengthwise direction and the main orientation direction of the helical chiral polymer (A) are substantially parallel to each other; the crystallinity measured by a DSC method is from 20% to 80%; and the birefringence is from 0.01 to 0.03.

A dielectric elastomer driving sensor system includes: a dielectric elastomer transducer portion including a dielectric elastomer layer and a pair of electrode layers that sandwich the dielectric elastomer layer, where the pair of electrode layers include a driving region and a sensor region that are partitioned from each other; a power supply unit that applies a voltage to the driving region; a detection unit that detects a change in capacitance in the sensor region; and a control unit that controls the power supply unit and the detection unit. With this configuration, both the driving function and the sensor function can be performed.

A piezoelectric transducer (100) comprises a piezoelectric foil (10) with a piezoelectric material (M) exhibiting a shear piezoelectric effect (d14). An actuating structure (20) is configured to actuate the foil with actuation forces (Fu, Fd) applied at respective actuation points (Au, Ad) in respective actuation directions (U, D) to bend the foil in two opposing bending directions (S1, S2), which are orthogonal to each other and both diagonal to the polarization direction (3) of the foil, according to a saddle shape deformation. Preferably, the foil (10) is wrapped around a flexible plate (15).