A biodegradable and biocompatible piezoelectric nanofiber platform for medical implant applications, including a highly sensitive, wireless, biodegradable force sensor for the monitoring of physiological pressures, and a biodegradable ultrasonic transducer for the delivery of therapeutics or pharmaceuticals across the blood-brain barrier.

The present invention relates to a piezoelectric fiber having excellent flexibility, the piezoelectric fiber employs a conductive fiber member as an inner electrode, on which a piezoelectric polymer layer, an outer electrode and a coating layer are sequentially formed, thereby having excellent flexibility and sufficient elasticity to be sewed, woven, knotted or braided. Therefore, the piezoelectric fiber can be applied in power supplies for a variety of sizes and types of wearable electronic devices, portable devices, clothing, etc. In addition, since the piezoelectric fiber has excellent piezoelectricity and durability because of the above-described structure, it can effectively convert deformation or vibration caused by external physical force into electric energy, and thus can replace existing ceramic-based and polymer piezoelectric bodies, etc. Furthermore, an economical and simple method of manufacturing a piezoelectric fiber having excellent piezoelectricity is provided.

Light emitting device and methods for forming the devices include a substrate and a nanowire placed on the substrate, where the nanowire comprises a core made of a semiconductor material. A cladding encloses the nanowire and has a breakdown voltage larger than a breakdown voltage of the core. A source of an electric field is provided, where the core is at least partially aligned with and lies at least partially within the electric field such that a cycling of the electric field creates charge separation and electron-hole recombination in the core.

Road signal systems and methods for controlling road signals include a piezoelectric layer integrated with a surface that undergoes stresses with traffic passing over the surface. A power collection circuit is configured to collect and store power from the piezoelectric layer. One or more devices receive electrical power from the power collection circuit responsive to traffic passing over the surface.

Road signal systems and methods for controlling road signals include a piezoelectric layer integrated with a surface that undergoes stresses with traffic passing over the surface. A power collection circuit is configured to collect and store power from the piezoelectric layer. One or more devices receive electrical power from the power collection circuit responsive to traffic passing over the surface.

Compact and power efficient acoustically actuated magnetoelectric antennas for transmitting and receiving very low frequency (VLF) electromagnetic waves utilize magnetoelectric coupling in a magnetic/piezoelectric heterostructure to provide voltage control of magnetization in transmission mode and magnetic control of electric polarization in receiving mode. The magnetoelectric antennas provide a power efficiency enhanced by orders of magnitude compared to magnetically or mechanically switching the magnetization. The antennas can be used in groups or arrays and can be combined to form VLF communication systems.

A filter that includes a plurality of fibers arranged to form a first principal surface and a second principal surface opposite the first principal surface, and a plurality of first piezoelectric fibers that generate negative charges by stretching are arranged at least on a side of the first principal surface.

A piezoelectric composite material includes a cross-linker and a plurality of ceramic fibers disposed in the cross-linker. The ceramic fibers include ABO.sub.3 oxide. A-site represents Pb.sub.xLa.sub.y containing lead (Pb) and lanthanum (La). In Pb.sub.xLa.sub.y, x ranges from 0.920 to 0.950, and y ranges from 0.050 to 0.080.

An antibacterial electric charge generation yarn meets requirements (a) to (e) mentioned below simultaneously and suppresses proliferation of bacteria by electric charge generated upon deformation of the yarn: (a) a main component of the yarn is polylactic acid.; (b) the yarn is twisted; (c) the yarn has a double torque of 50 T/50 cm or less; (d) the yarn has a single fiber fineness of 0.05 to 5 dtex; and (e) the number of filaments in the yarn is 10 to 400.

Haptic feedback is provided by rendering haptic effects on a haptically-enabled device that includes a front screen, a back cover coupled to the front screen, and a haptic output device attached to or formed within the front screen or the back cover. The haptic output device is configured to render a high-definition (HD) vibratory haptic effect, a low-frequency vibratory haptic effect, and a deformation haptic effect.