A flexible vibration module is disclosed. The flexible vibration module includes a piezoelectric composite layer, including: a plurality of piezoelectric portions each having a piezoelectric characteristic, where at least two of the plurality of piezoelectric portions have different sizes; and a flexible portion between the plurality of piezoelectric portions.

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.

Methods and systems for sending multicast messages are disclosed. A multicast message is received to be transmitted to a plurality of access terminals at a radio access network (RAN), the received multicast message having a first format. The first format may correspond to a conventional multicast message format. The RAN determines whether the received multicast message requires special handling. If the RAN determines the received multicast message requires special handling, the radio access network converts the received multicast message from the first format into a second format. The RAN transmits the converted multicast message with the second format (e.g., a data over signaling (DOS) message) on a control channel to at least one of the plurality of access terminals. The access terminals receiving the converted multicast message interpret the message as a multicast message.

An actuator includes a laminate including an elastomer layer and an electrode, in which the laminate has a spiral or concentric shape, pre-distortion is applied to at least one member out of the elastomer layer and the electrode, and area distortion of the at least one member is 10% or larger.

Piezoelectric vibrational energy harvesters (PVEHs) include a Macro Fiber Composite (MFC)) piezoelectric transducer coupled to a cantilever to harvest vibrational energy. One or more Ionic Polymer Metal Composite (IPMC) strips are situated to provide device tuning over a wide frequency range by applying variable contact force to the cantilever. Power consumption for tuning is sufficiently low that the tuning actuator (IPMCs) can be powered using harvested energy.

Provided is a piezoelectric structure comprising a braid composed of a conductive fiber and piezoelectric fibers, the braid being a covered fiber having the conductive fiber as the core and the piezoelectric fibers covering the periphery of the conductive fiber, wherein the covered fiber has at least one bent section, and when the piezoelectric structure is placed on a horizontal surface, the height from the horizontal surface to the uppermost section of the piezoelectric structure is greater than the diameter of the covered fiber.

The purpose of the present invention is to provide a fibrous piezoelectric element which enables a large electric signal to be drawn out by stress produced by relatively small deformation. A piezoelectric element includes a braid composed of a conductive fiber and a piezoelectric fiber. In the braid, the conductive fiber is a core, and the piezoelectric fiber is a covering fiber that covers the periphery of the conductive fiber.

A piezoelectric fiber composite that includes a substrate having a first expansion and contraction rate, a piezoelectric fiber assembly having piezoelectric fibers that generate electrical charges upon application of external energy and has a second expansion and contraction rate different from the first expansion and contraction rate of the substrate, and a joint portion that joins the substrate and the piezoelectric fiber assembly.

A flexible vibration module is disclosed. The flexible vibration module includes a piezoelectric composite layer, including: a plurality of piezoelectric portions each having a piezoelectric characteristic, where at least two of the plurality of piezoelectric portions have different sizes; and a flexible portion between the plurality of piezoelectric portions.

An antibacterial mask that includes a filter portion having a first layer and a second layer, wherein the first layer includes a plurality of first piezoelectric yarns that generate at least a first charge by stretching, and the second layer is formed of an ordinary cloth and positioned on a user side of the antibacterial mask.