The present invention relates to transducers, their use and fabrication. The transducers convert between mechanical and electrical energy. Some transducers of the present invention include a pre-strained polymer. The pre-strain improves the conversion between electrical and mechanical energy. The present invention also relates to devices including an electroactive polymer to convert between electrical and mechanical energy. The present invention further relates to compliant electrodes that conform to the shape of a polymer included in a transducer. The present invention provides methods for fabricating electromechanical devices including one or more electroactive polymers.

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In this paper we present a framework that allows the haptic rendering of interactions between the human hand and a virtual environment consisting of polygonal objects. The proposed solution creates a representation of the human hand through simple geometric primitives (spheres, cylinders etc.) and allows the fast collision detection and calculation of forces of interaction. Theforces are calculated with precision and smoothness, especially at the fingertips, where the human haptic perception is more sensitive. The area of each contacted region is taken into account to correctly weigh the importance of each force we calculate.The objective is to give a simulation tool that will allow the use of exoskeletons for the human hand with an improved level ofprecision, which is necessary for the correct evaluation of these haptic devices and their efficient use.

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A wireless lifting assist device includes a pulley driven by an actuator which is attached to a ceiling. An end-effector is suspended, via a line, from the pulley and interfaces the object to be maneuvered. The wireless lifting assist device further provides an instrumented glove worn by an operator. The glove measures the contact force the operator is exerting on either the object to be moved or the lifting assist device and generates a set of contact signals representing the contact force. The contact signals are transmitted to a controller. The controller generates a set of command signals to control the actuator as a function of the operator contact force such that a predetermined percentage of the force necessary to lift or lower the load is applied by the actuator, with the remaining force being supplied by the operator. The object thus feels lighter to the operator.

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Drop foot, a loss of use of the muscles that lift the foot, can be caused by stroke, cerebral palsy (CP), multiple sclerosis (MS), or neurological trauma. The two major complications of drop foot are slapping of the foot after heel strike (foot slap) and dragging of the toe during swing (toe drag). The current assistive device is the Ankle Foot Orthosis (AFO), which though offering some biomechanical benefits, is non-adaptive and fails to eliminate significant gait complications. An Active Ankle Foot Orthosis (AAFO) is presented where the impedance of the orthotic joint is modulated throughout the walking cycle to treat drop foot gait. To prevent foot slap, a biomimetic torsional spring control is applied where orthotic joint stiffness is actively adjusted to mi-nimize forefoot collisions with the ground. Throughout late stance, joint impedance is minimized so as not to impede powered plan-tar flexion movements, and during the swing phase, a torsional spring-damper (PD) control lifts the foot to provide toe clearance. To assess the clinical effects of variable-impedance control, kinetic and kinematic gait data were collected on two drop foot parti-cipants wearing the AAFO. For each participant, zero, constant and variable impedance control strategies were evaluated, and the re-sults were compared to the mechanics of three age, weight and height matched normals. It was found that actively adjusting joint im-pedance significantly reduces the occurrence of slap foot, allows greater powered plantar flexion, and provides for greater biolo-gical realism in swing phase ankle dynamics. These results indicate that a variable-impedance orthosis may have certain clinical benefits for the treatment of drop foot gait compared to conventional AFO having zero or constant stiffness joint behaviors.

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The purpose of this technical note is to report the development of a cell-based assay for the detection of endocrine disrupting activity related to crustacean and insect molting and to provide a detailed laboratory protocol for its conduct.

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