The disclosed embodiments are generally directed to optical systems. The optical systems may include a proximal lens that may transmit light toward an eye of a user. The optical systems may also include a distal lens that may, in combination with the proximal lens, correct for at least a portion of a refractive error of the eye of the user. The optical systems may further include a selective transmission interface. The selective transmission interface may couple the proximal lens to the distal lens, transmits light having a selected property, and does not transmit light that does not have the selected property. The optical system can also include an accommodative lens, such as a liquid lens. Various other methods, systems, and computer-readable media are also disclosed.

An object is to provide a fluorine-containing polymer film. The object can be achieved by a fluorine-containing polymer film having a thermal shrinkage of 0.4% or less after being heated at 90° C. for 1 hour, and having a relative permittivity of 3 to 50 at 25° C. at 1000 Hz, or a fluorine-containing polymer film having a crystallinity of 50% or more and an elongation at break of 400% or more.

An electroactive device may include (1) an electroactive polymer element having a first surface and a second surface opposite the first surface, the electroactive polymer element comprising a nanovoided polymer material, (2) a primary electrode abutting the first surface of the electroactive polymer element, and (3) a secondary electrode abutting the second surface of the electroactive polymer element. The electroactive polymer element may be deformable from an initial state to a deformed state by application of an electrostatic field produced by a potential difference between the primary electrode and the secondary electrode. Various other devices, systems, and methods are also disclosed.

An object of the present invention is to improve the piezoelectricity of a PVT having the VDF ratio of 82 to 90% represented by a copolymer, in which copolymerization of vinylidene fluoride VDF and trifluoroethylene TrFe is 85 versus 15 (this is written as PVT85/15, and which is excellent in resistance to deformation, and heat resistance, etc. And therefore, it is also to obtain a piezoelectric film having piezoelectricity exceeding a PVT of less than 82 mol % of VDF represented by a PVT75/25, which conventionally shows the highest piezoelectricity, and a method of producing the same. A piezoelectric film is made of a mixture of two kinds (for example, a first copolymer is PVT85/15 and a second copolymer is PVT75/25) having different polymerization ratios of vinylidene fluoride VDF and trifluoroethylene TrFE.

A sensing film includes a base layer, a piezoelectric layer formed on the base layer, and a first electrode and a second electrode formed on the piezoelectric layer. The first and second electrodes are spaced apart and electrically insulated from each other. The first electrode includes a first connecting portion and a number of first extending portions coupled to the first connecting portion. The second electrode includes a second connecting portion and a number of second extending portions coupled to the second connecting portion. The first connecting portion and the second connecting portion are spaced apart and face each other. The first extending portions extend from a side of the first connecting portion toward the second connecting portion. The second extending portions extend from a side of the second connecting portion toward the first connecting portion. The first extending portions and the second extending portions are alternately arranged.

A piezoelectric device and method of manufacturing are described. A first substrate is provided with an array of pillars comprising piezoelectric material. A second substrate is provided with a piezoelectric layer facing respective ends of the pillars. The respective ends of the pillars are pushed into the piezoelectric layer, while the piezoelectric layer is at least partially liquid. The piezoelectric layer is solidified to form an integral connection between the piezoelectric layer and the pillars. The piezoelectric layer can thus form a bridging structure between the respective ends of the pillars. The integral piezoelectric structure can be poled by high voltage. The bridging structure can act as a platform for depositing electrical contacts. The piezoelectric device can be used for generating or detecting acoustic waves, e.g. in medical imaging.

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 output of a bending-strain-based transducer element is used for both energy scavenging and as a sensor signal indicative of a user parameter, such as a step, respiration rate, heart rate, weight and the like. In some embodiments, a transducer element includes a plurality of piezoelectric layers that are electrically connected in parallel to increase the energy and/or power provided by the transducer element.

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 output of a bending-strain-based transducer element is used for both energy scavenging and as a sensor signal indicative of a user parameter, such as a step, respiration rate, heart rate, weight and the like. In some embodiments, a transducer element includes a plurality of piezoelectric layers that are electrically connected in parallel to increase the energy and/or power provided by the transducer element.

Use of an elastomeric film in the form of a gel, wherein said gel is a non-conductive hydrogel or organogel, as a dielectric electroactive polymer.

VDF-co-(TFE or TrFE) polymers having a molecular weight of at least about 1,000,000 g/mol and a melt temperature less than about 240° C. The VDF copolymer contains at least about 50 mol % VDF monomer and may include an amount of at least one other monomer. The VDF copolymer may be used to form a membrane that has a node and fibril structure. The membrane has a percent porosity of at least 25%. A VDF-co-(TFE or TrFE) polymer membrane may be formed by lubricating the VDF copolymer, subjecting the lubricated polymer to pressure at a temperature below the melting point of the VDF copolymer to form a preform material, and expanding the preform material at a temperature below the melting temperature of the VDF copolymer. Dense VDF copolymer articles, filled VDF copolymer membranes, and VDF copolymer fibers are also provided.