Abstract: The present invention provides an electrospray device using a high frequency alternating current (AC) above 10 kHz to generate fine micron sized drops. The apparatus generally functions by applying a high frequency alternating current electric field across one or more micro-needles and one or more conducting elements. The present invention may be used to generate aerosol drops for respiratory drug delivery or as a microencapsulation technique for the encapsulation of drugs, DNA, protein, osteogenic or dermatological growth factors, bacteria, viruses, immobilized enzyme receptors and fluorescent particles for controlled release drug delivery, tissue or bone engineering, clinical or environmental field testing and as biosensors for clinical or drug monitoring. In addition, the present invention may be used to synthesize biodegradable fibers as bioscaffolds for tissue engineering, surgical sutures or medical gauze that enhance blood coagulation, and further may be encapsulated by other agents.

Abstract: Disposable dosimeter for sun radiation comprising polymeric matrix with distributed therein at least one active chemical compound capable to change its original color to a new color due to a reversible photo-chemical reaction induced upon exposing the dosimeter to UV radiation. The transparency of the matrix is sufficient to enable easy visual detection of the change of the original color to the new color. The matrix is provided with porous structure suitable for absorbing thereinto of a sunscreen loti n when it is applied to the dosimeter.

Abstract: A reusable dosimeter for sun radiation comprising a matrix with at least one active chemical compound distributed therein, capable of reversibly changing its original color to a new color due to a chemical reaction induced by exposure to UV radiation, said matrix made of a material having transparency sufficient for visual detection the change of the original compound's color to the new color, said active chemical compound being capable of changing its color after exposure to UV radiation with an efficacy corresponding to at least 1 MED, and reverting back to its original color after being kept in the dark for about 6 hours.

Abstract: A disposable dosimeter for sun radiation comprising a matrix with at least one active chemical compound distributed therein, capable of changing its original color to a new color due to a chemical reaction induced by exposure to UV radiation, said matrix made of a material having transparency sufficient for visual detection the change of the original compound's color to the new color, said matrix containing at least one absorbing compound capable of absorbing the UV radiation, said active chemical compound being capable of changing its color after exposure to UV radiation with an efficacy corresponding to at least 1 MED, said UV radiation being accumulated during at least 15 minutes of exposure and said active chemical compound having a resistance to change the new color neither during exposure to temperatures up to 50.degree. C., nor during exposure to visible light.