Abstract: A case-neutral electrochemical cell comprises a jellyroll electrode assembly housed inside a cylindrically shaped casing. The anode has a tab connected to the perimeter of a metallic couple residing between a casing header and the electrode assembly. Separately, an anode lead is connected to the couple. This establishes continuity from the anode tab connected to the couple in turn connected to the anode lead extending from the couple and then in a non-conductive relationship through the header to serve as the negative terminal for the cell. A cathode lead, which had previously served as a winding mandrel for the electrode assembly, extends in a non-conductive relationship through both the couple and a second opening in the header. That way, the anode and cathode leads are both electrically isolated from the casing comprising the header closing an open-ended container housing the electrode assembly to provide the case-neutral cell design.

Abstract: Similar to combustion engines including multiple cylinders engaged with a crankshaft, multiple piezoelectric stack actuators (PSA) engaged with a common output rod can produce smooth, long stroke motion with desired properties. In particular, when equally spaced multiple units are arranged to push sinusoidal gear teeth on the output rod, the system exhibits unique collective behaviors thanks to “harmonic” effects of the multiple units. For example, although the force-displacement characteristics of individual units are highly nonlinear, the undesirable nonlinearity, including singularity, may be eliminated. Here it presents harmonic analysis, design, and control of a class of actuators consisting of multiple driving units engaged with a sinusoidal transmission, termed a harmonic poly-actuator.

Abstract: Mechanically simple, reliable devices for measuring pressure or detecting pressures above a certain limit are disclosed. A representative device includes a magnet surrounded by one or more bands of a ferrofluid, and which is free to move within a nonmagnetic, generally elongated housing. In operation, the housing is oriented vertically, and the lower aperture exposed to the region of pressure to be sensed. The opposite end, which preferably contains another aperture, is exposed to a reference pressure (ordinarily the atmosphere) that remains isolated from the region of pressure to be sensed. Gravity draws the magnet downward, toward the bottom of the housing, while pressure at the lower aperture tends to force the magnet upward. When the force exerted by the pressure source exceeds the downward force of gravity, the magnet travels upward through the housing; this movement may be detected by an appropriate sensing arrangement, and is used to provide a warning signal or a quantitative pressure measurement.