Abstract: Footwear comprises a sole and a plurality of sealed cavities contained within the sole. The sealed cavities can be incorporated as deformable containers within an elastic medium, comprising the sole. A plurality of micro electro-mechanical system (MEMS) pressure sensors are respectively contained within the sealed cavity plurality, and can be adapted to measure static and dynamic pressure within each of the sealed cavities. The pressure measurements can provide information relating to the contact pressure distribution between the sole of the footwear and the wearer's environment.

Abstract: A method for making a braze joint across a discontinuity in a work piece using alternating current. A filler metal is pre-placed at a location sufficiently close to the discontinuity such that, when an alternating current is applied across a work piece to heat the work piece and melt the filler metal, the filler metal is drawn into the discontinuity. The alternating current is maintained for a set residence time, generally less than 10 seconds and more particularly less than 3 seconds. The alternating current is then altered, generally by reducing the current and/or voltage such that the filler metal can solidify to form a braze joint of desired quality and thickness.

Abstract: Structures for use in conjunction with surface micromachined structures are formed using a two-step etching process. In various exemplary embodiments, the two-step etching process comprises a modified Bosch etch. According to various exemplary embodiments of the two-step etch, first mask and second masks are used to prepare a layer for etching one or more desired structures. The first mask is used to define at least one large feature. The second mask is used to define at least one small feature (small as compared to the at least one large feature). The second mask is formed over the first mask which is formed over the layer. In the first etching step, the at least one small feature is etched into the layer. Then, the second mask is removed using the chemical rinsing agent. In the second etching step, the at least one large feature is etched into the layer such that the at least one small feature propagates further into the layer ahead of the at least one large feature. The first mask is then removed.

Abstract: An electronic drive system applies a drive signal to an electrostatically actuated device such that a resulting electric field has a constant force. In various exemplary embodiments, the electronic drive system applies a drive signal to an electrostatically actuated fluid ejector that has a piston and a faceplate including a nozzle hole. A dielectric fluid to be ejected is supplied between the piston and the faceplate. The drive signal is applied to one of the piston and the faceplate. The drive signal generates an electric field across the fluid between the piston and the faceplate. The electric field causes the piston to be electrostatically attracted towards the faceplate so that a jet or drop of fluid is ejected through the nozzle hole of the faceplate. According to exemplary embodiments, the drive signal is from a constant current source or is reduced over the course of its lifetime.

Abstract: A piston structure is movably mounted within a fluid chamber. Movement of the piston structure towards a faceplate causes a portion of the fluid between the piston and the faceplate to be forced out of the nozzle hole in the faceplate, forming a drop or jet of the fluid. Viscous forces that are generated by the flow of fluid along a working surface of the piston structure toward and away from the nozzle hole generate a force that resists the movement of the piston structure. This resistance force tends to slow the piston motion, and prevents the piston from contacting the faceplate. In various embodiments, the fluid chamber is defined by a cylinder structure. The piston structure moves within the cylinder structure. The cylinder structure and the faceplate define the fluid chamber. The cylinder structure and the piston structure are designed to cooperate so that the movement of the piston structure within the cylinder structure ejects fluid according to various design criteria.

Abstract: A bi-directional fluid ejector according to the systems and methods of this invention operates on the principle of electrostatic attraction. In various exemplary embodiments, the fluid ejector includes a sealed dual diaphragm arrangement, an electrode arrangement that is parallel and opposite to the sealed diaphragms, and a structure which contains the fluid to be ejected. A diaphragm chamber containing a relatively incompressible fluid is situated behind, and is sealed by, the diaphragms. At least one nozzle hole is formed in a faceplate of the ejector over one of the diaphragms. A drive signal is applied to at least one electrode of the electrode arrangement to generate an electrostatic field between the electrode and a first one of the diaphragms. The first diaphragm is attracted towards the electrode by an electrostatic force into a deformed shape due to the electrostatic field. Upon deforming, pressure is transmitted to a second one of the sealed diaphragms.

Abstract: A fluid ejection system according to this invention operates on the principle of electrostatic or magnetic attraction. In various exemplary embodiments, the fluid ejection system includes a sealed diaphragm arrangement having at least one diaphragm portion and a diaphragm chamber defined at least partially by the at least one diaphragm portion, a nozzle hole located over the at least one diaphragm portion, an ejection chamber defined between the nozzle hole and the least one diaphragm portion and a secondary dielectric fluid reservoir containing a secondary dielectric fluid. The ejection chamber receives a primary fluid to be ejected. The secondary dielectric fluid reservoir is in fluid communication with the diaphragm chamber to supply the secondary dielectric fluid to the diaphragm chamber. In various exemplary embodiments, the secondary dielectric fluid is a liquid, a substantially incompressible fluid, and/or a high performance dielectric fluid having a dielectric constant greater than 1.

Abstract: An electrostatic microelectromechanical system (MEMS) based fluid ejector comprises a movable piston structure and a stationary faceplate. A fluid chamber is defined between the piston structure and a substrate. The piston structure 110 may be resiliently mounted on the substrate by one or more spring elements. A fluid to be ejected is supplied in the fluid chamber from a fluid reservoir through a fluid refill hole formed in the substrate. The faceplate includes a nozzle hole through which a fluid jet or drop is ejected. In various exemplary embodiments, the piston structure moves towards the faceplate by electrostatic attraction between the piston structure and the faceplate. As a result of the movement of the piston structure, a portion of the fluid between the piston structure and the faceplate is forced out of the nozzle hole, forming a jet or drop of the fluid.

Abstract: The systems and methods of the present invention operate by magnetically driving a fluid ejector. In various exemplary embodiments, a primary coil and a secondary coil are situated in the ejector. The ejector has a movable piston usable to eject fluid through a nozzle hole. The piston may be resiliently mounted and biased to an at-rest position. A drive signal is applied to cause current to flow in the primary coil. The current flow generates a magnetic field that induces a current in the secondary coil. Either the primary coil or the secondary coil or associated with the piston and the other is associated with a fixed structure of the ejector. As a result, a magnetic force is generated that pushes the piston either toward a faceplate so that a drop of fluid is ejected through the nozzle hole in the faceplate or away from the faceplate so that fluid fills in a fluid chamber between the piston and the faceplate.