In this paper we describe a novel method for detecting bends and folds in fabric structures. Bending and folding can be used to detect human joint angles directly, or to detect possible errors in the signals of other joint-movement sensors due to fabric folding. Detection is achieved through measuring changes in the resistance of a complex stitch, formed by an industrial coverstitch machine using an uninsulated conductive yarn, on the surface of the fabric. We evaluate self-intersecting folds which cause short-circuits in the sensor, creating a quasi-binary resistance response, and non-contact bends, which deform the stitch structure and result in a more linear response. Folds and bends created by human movement were measured on the dorsal and lateral knee of both a robotic mannequin and a human. Preliminary results are promising. Both dorsal and lateral stitches showed repeatable characteristics during testing on a mechanical mannequin and a human.

An effective way to monitor body movements and positions (including physiological signals like breathing) without causing discomfort is through integration of sensors and electronics into base layers of clothing. However, for many applications (including sports and fitness), such sensors must be washable. Here, we present results of experiments evaluating the impact of washing on an e-textile stretch and bend sensor. Two cases are investigated: un-insulated sensors and sensors insulated with a fusible polymer film. Results show small-scale drift in the un-insulated sensor, which is magnified by machine washing and further by machine drying. Similar results are observed in delamination effects for the insulating film.

Josephson primary voltage standards require a ERROR VOLTAGE I--------frequency-locked 77 GHz signal to perform precise frequencyto-voltage conversion. We describe the development of superconducting frequency counters used for microwave source locking in Josephson junction array primary voltage standards, and discuss design challenges and high speed test results. The counters increase the accessibility of Josephson standards by reducing the size, number of components, and cost of these systems.

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