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.

An optical element includes a nanovoided polymer layer having a first refractive index in an unactuated state and a second refractive index different than the first refractive index in an actuated state. Compression or expansion of the nanovoided polymer layer, for instance, can be used to reversibly control the size and shape of the nanovoids within the polymer layer and hence tune its refractive index over a range of values, e.g., during operation of the optical element. Various other apparatuses, systems, materials, and methods are also disclosed.

In some example embodiments, a stretchable organic optoelectronic sensorimotor synapse comprises: a photodetector triggered by optical signals to generate voltage pulses; and a stretchable organic nanowire synaptic transistor (s-ONWST) driven by the voltage pulses to generate resultant informative synaptic outputs.

A display device includes a first substrate and a second substrate at which a display area for displaying an image and a non-display area surrounding the display area are provided; a light-emitting diode in the display area on an inner surface of the first substrate and including an anode electrode, a light-emitting layer and a cathode electrode; and a piezoelectric element in the display area on an inner surface of the second substrate and including a first electrode, a piezoelectric layer and a second electrode, wherein the piezoelectric layer includes dichroic dyes.

A piezoelectric stack includes a porous resin sheet, and a surface coating layer disposed on an exterior surface of the porous resin sheet, the exterior surface including at least one of a front surface and a back surface of the porous resin sheet, the surface coating layer having a volume resistivity of not less than 1×10.sup.13 Ω.Math.cm, the porous resin sheet and the surface coating layer having different elastic moduli.

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.

A display apparatus includes a display panel configured to display an image and a sound generating device on a rear surface of the display panel. The sound generating device is configured to vibrate the display panel to generate sound. The sound generating device includes a first structure and a first passivation layer on one side of the first structure, at least a portion of the first passivation layer having a non-flat shape.

In some examples, a device includes a nanovoided polymer element, a planarization layer disposed on a surface of the nanovoided polymer element, a first electrode disposed on the planarization layer, and a second electrode. The nanovoided polymer element may be located at least in part between the first electrode and the second electrode. The planarization layer may be located between the nanovoided polymer element and the first electrode.

The present invention relates to a piezoelectric sensor using a piezoelectric polyvinylidene fluoride (PVDF) film. As an embodiment, there is proposed a piezoelectric sensor including: a PVDF film; an electrode layer which is formed on the top surface of the PVDF film; a substrate which is provided with a first electrode electrically connected to the electrode layer and a second electrode disposed at a location spaced apart from the first electrode; a non-conductive layer which covers the electrode layer; a first shield film which is electrically connected to the second electrode while being attached to the non-conductive layer; and a second shield film which is attached to the top surface of the PVDF film, and is connected to the first shield film while surrounding a stack of the PVDF film to the non-conductive layer.

Sensing an environment by confining a monitored live subject in an enclosure, detecting an effect on a coaxial piezoelectric cable resulting from the monitored live subject, wherein the coaxial piezoelectric cable is located at least proximate to the enclosure, and deriving information about a state of the monitored live subject based on the detected effect.