Abstract: A method for predicting failures in crystalline microstructures is described. Fracture stress distribution data obtained from test samples prepared according to the same manufacturing process as a contemplated device is used to characterize the strength of surfaces in a numerical stress analysis of the device. The failure probability is then calculated for surface nodes on the device. The product of all such probabilities yields the overall probability of failure of the device.

Abstract: Methods and systems for providing gesture-based power management for a wearable portable electronic device with display are described. An inertial sensor is calibrated to a reference orientation relative to gravity. Motion of the portable device is tracked with respect to the reference orientation, and the display is enabled when the device is within a viewable range, wherein the viewable range is a predefined rotational angle range in each of x, y, and z axis, to a user based upon a position of the device with respect to the reference orientation. Furthermore, the display is turned off if an object is detected within a predetermined distance of the display for a predetermined amount of time.

Abstract: The present invention provides an ultrasonic resonant cavity droplet ejector with localized excitation and a method for making the same. In a resonant cavity with an ultrasonic transducer acting as one of the cavity walls, the energy input from the transducer coupled with the gain of the resonant cavity causes a droplet to be ejected from a nozzle in the cavity wall. In addition, a refill channel can be introduced such that the cavity can be refilled without affecting cavity gain. Arrays of such locally excitable ejector cavities are useful in numerous applications, including, among others, ink-jet printing, DNA chip printing, and fuel injectors.

Abstract: A micromachined accelerometer for measuring acceleration in a direction parallel with the plane of the accelerometer substrate. The accelerometer has a strain-isolation pedestal, a flexure attached to the pedestal, and a proof mass attached to the flexure. The pedestal is wider than the flexure and does not bend when the device is under acceleration. The pedestal serves to isolate the flexure from substrate strain which may be caused by device packaging or temperature variations. Preferably, the joint between the pedestal and flexure, and the joint between the flexure and proof mass are smoothed to prevent stress concentration. The joints have a radius of curvature of at least 1 micron. A piezoresistor is located in one sidewall of the flexure. Alternatively, two piezoresistors are located on the flexure, with one on each sidewall. In this embodiment, a center-tap connection is provided to the point where the two piezoresistors are connected.