Xerox Corporation

Sandia Corporation

Frank J Peter

Paul Charles Galambos

George J Roller

Arthur M Gooray

Kevin R Zavadil

Richard C Givler

Joseph Michael Crowley

Michael Baker

Jeffrey C Gilkey

Michelle A Duesterhaus

Rosemarie A Renn

Jeffry Joseph Sniegowski

Randy J Shul

Michael A Butler

Leonard M Carreira

William M Lindenfelser

David W Plummer

D Russell Humphreys

George R Laguna

Christi Willison Gober

Joseph M Crowley, Jr

Larry J Dalton

A first-in-first-out (FIFO) microelectromechanical memory apparatus (also termed a mechanical memory) is disclosed. The mechanical memory utilizes a plurality of memory cells, with each memory cell having a beam which can be bowed in either of two directions of curvature to indicate two different logic states for that memory cell. The memory cells can be arranged around a wheel which operates as a clocking actuator to serially shift data from one memory cell to the next. The mechanical memory can be formed using conventional surface micromachining, and can be formed as either a nonvolatile memory or as a volatile memory.

Mechanical memory

A new class of mechanical code comparators is described which have broad potential for application in safety, surety, and security applications. These devices can be implemented as micro-scale electromechanical systems that isolate a secure or otherwise controlled device until an access code is entered. This access code is converted into a series of mechanical inputs to the mechanical code comparator, which compares the access code to a pre-input combination, entered previously into the mechanical code comparator by an operator at the system security control point. These devices provide extremely high levels of robust security. Being totally mechanical in operation, an access control system properly based on such devices cannot be circumvented by software attack alone.

Mechanical code comparator

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. Other surface micromachined methods and structures are provided as well.

Surface micromachined structure fabrication methods for a fluid ejection device

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. Further, according to various exemplary embodiments, the drive signal is of a suitable high frequency to reduce the potential of electrochemical reactions or electrical breakdown, or both. The drive signal may also be a bi-polar drive signal to reduce the possibility of electrochemical reactions.

Electronic drive systems and methods

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. In various embodiments, a free space is provided between the faceplate and the piston structure at its maximum displacement towards the faceplate.

Micromachined fluid ejector systems and methods having improved response characteristics

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. The transmitted pressure and the relatively incompressible nature of the fluid contained within the sealed diaphragm chamber causes the second diaphragm to deflect in the opposite direction to force fluid through at least one of the at least one nozzle hole. After a drop is ejected, the movement is reversed, either through normal resilient restoration actions of the deformed diaphragm and/or through an applied force.

Bi-directional fluid ejection systems and methods

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.

Fluid ejection systems and methods with secondary dielectric fluid

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 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.

Micromachined fluid ejector systems and methods

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. When the drive signal is turned off, the piston resiliently returns to its at-rest position, thereby either refilling the ejected fluid or ejecting a drop of fluid through the nozzle hole in the faceplate. In various other embodiments, the faceplate is made of a magnetic material, such as a ferrous material, or is coated with or connected to a magnetic material. A second primary coil or a permanent magnet may be included in various other embodiments. In various embodiments, switching the direction of the current changes the magnetic force between attraction and repulsion.

Magnetic drive systems and methods for a micromachined fluid ejector

A new chemical probe determines the properties of an analyte using the light absorption of the products of a reagent/analyte reaction. The probe places a small reaction volume in contact with a large analyte volume. Analyte diffuses into the reaction volume. Reagent is selectively supplied to the reaction volume. The light absorption of the reaction in the reaction volume indicates properties of the original analyte. The probe is suitable for repeated use in remote or hostile environments. It does not require physical sampling of the analyte or result in significant regent contamination of the analyte reservoir.

Growing community of inventors

Albuquerque, NM, United States of America

Frank J Peter