Confocal microscopy methods have been employed to image the metathoracic trochanter, a small exoskeleton segment between the coxa and femur, of an adult cockroach, Periplaneta americana. The confocal images represent planar sections through the exoskeleton of the trochanter. Specia-lized software was implemented to convert the section images into a complete three-dimensional geometric model of the trochanter. The raster image data of the confocal model was exported in a vector file format. Custom software was developed to resample the vector data and to automatically create a finite element mesh. The resulting mesh contained first-order, three-dimensional, triangular plate elements and also encoded data for element thicknesses. The Algor finite element package was used to analyze the model under the conditions of several biologically pertinent experiments. Special emphasis was placed on the strain analysis of the four groups of campaniform sensilla on the trochanter. These sensory organs respond to strains in the exoskeleton and are instrumental in the control of natural walking in insects. The results were compared to data from biological experiments which confirmed hypotheses and answered questions that have been difficult to determine experimentally on the animal. Functional differentiation both between groups and within groups of sensilla was observed. Further evidence that strain measurements are used in positive feedback control of the trochanteral extensor muscles was discovered. The structure of the trochanter was analyzed in the context of the function of the campaniform sensilla. Previously undescribed quantitative stress and strain data for insect cuticle was recorded.

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A system for determining acceleration by measuring the movement of a rod within a housing. The rod is an elongate flexible rod disposed in the housing with one end being attached to the housing and the other end being free to move when the housing is accelerated. Movement of the rod is measured with field detectors disposed on an inside wall of the housing. The field detectors are used for determining the direction and degree of movement of the rod when the housing is accelerated.

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A movement actuator includes an elongate filament made of a flexible material, and a strip of shape memory alloy disposed on the surface of one side of the filament. The shape memory alloy is responsive to actuation signals, heat or electrical signals, for changing its shape and when its shape changes, it causes the filament to move, i.e., bend, to accommodate the change in shape of the alloy. Also included is a signal supply device for selectively applying heat signals or electrical current to the strip of shape memory alloy to causes the alloy to change its shape and cause the filament to bend. Other patterns for the shape memory alloy could be disposed on the filament to cause other kinds of movements. For example, a helical pattern of the shape memory alloy about the filament would cause the filament to twist when the helical pattern were caused to shorten or lengthen.

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