Two recursive and numerically stable matrix algorithms for modeling layered diffraction gratings, the S-matrix algorithm and the R-matrix algorithm, are systematically presented in a form that is independent of the underlying grating models, geometries, and mountings. Many implementation variants of the algorithms are also presented. Their physical interpretations are given, and their numerical stabilities and efficiencies are discussed in detail. The single most important criterion for achieving unconditional numerical stability with both algorithms is to avoid the exponentially growing functions in every step of the matrix recursion. From the viewpoint of numerical efficiency, the S-matrix algorithm is generally preferred to the R-matrix algorithm, but exceptional cases are noted.

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Formulation and comparison of two recursive matrix algorithms for modeling layered diffraction gratings

The present invention is directed to a drug delivery pump apparatus, which comprises: (a) an expandable and contractible enclosure having an interior volume that defines a medication reservoir; (b) one or more electroactive polymer actuators; (c) a medication outlet port providing fluid communication between the interior volume of the contractible and expandable enclosure and an exterior of the delivery pump apparatus; and (d) a control unit electrically coupled to the one or more actuators and sending control signals to the same. The one or more electroactive polymer actuators act to reduce the interior volume of the contractible and expandable enclosure based upon the received control signals. The present invention is also directed to a method of delivering a liquid therapeutic agent to a patient. The method comprises: (a) providing the above infusion pump apparatus; (b) placing the outlet port of the infusion pump apparatus in fluid communication with a patient; and (c) sending the control signals to the one or more actuators to reduce the internal volume of the contractible and expandable enclosure, thereby forcing a portion of the liquid therapeutic agent within the medication reservoir through the outlet port and into the patient.

Electroactive polymer actuated medication infusion pumps

The invention describes devices for performing thermodynamic work on a fluid, such as pumps, compressors and fans. The thermodynamic work may be used to provide a driving force for moving the fluid. Work performed on the fluid may be transmitted to other devices, such as a piston in a hydraulic actuation device. The devices may include one or more electroactive polymer transducers with an electroactive polymer that deflects in response to an application of an electric field. The electroactive polymer may be in contact with a fluid where the deflection of the electroactive polymer may be used to perform thermodynamic work on the fluid. The devices may be designed to efficiently operate at a plurality of operating conditions, such as operating conditions that produce an acoustic signal above or below the human hearing range. The devices may be used in thermal control systems, such as refrigeration system, cooling systems and heating systems.

Electroactive polymer devices for moving fluid

The invention describes rolled electroactive polymer devices. The invention also describes employment of these devices in a wide array of applications and methods for their fabrication. A rolled electroactive polymer device converts between electrical and mechanical energy; and includes a rolled electroactive polymer and at least two electrodes to provide the mechanical/electrical energy conversion. Prestrain is typically applied to the polymer. In one embodiment, a rolled electroactive polymer device employs a mechanism, such as a spring, that provides a force to prestrain the polymer. Since prestrain improves mechanical/electrical energy conversion for many electroactive polymers, the mechanism thus improves performance of the rolled electroactive polymer device.

Rolled electroactive polymers

A through-wafer interconnect for imager, memory and other integrated circuit applications is disclosed, thereby eliminating the need for wire bonding, making devices incorporating such interconnects stackable and enabling wafer level packaging for imager devices. Further, a smaller and more reliable die package is achieved and circuit parasitics (e.g., L and R) are reduced due to the reduced signal path lengths.

Through-wafer interconnects for photoimager and memory wafers

A method for forming lenslets which collect light and focus the light onto photosensitive elements of an electronic imager. The method includes providing a transparent lenslet-forming layer on a substrate or on layers on the substrate, forming a thin etch-stop layer on the transparent lenslet-forming layer and patterning a thin photosensitive resin mask on the etch-stop layer so that the mask pattern corresponds to lenslets to be formed. The method further includes transferring by etching the pattern of the photosensitive resin mask to the thin etch-stop layer to form a thin etch-stop mask, anisotropically plasma etching the transparent lenslet-forming layer according to the patterned thin etch-stop mask, removing the thin etch-stop mask, and thermally reflowing the etched transparent lenslet-forming layer to form the lenslets.

Pattern transfer techniques for fabrication of lenslet arrays for solid state imagers

We made a high-efficiency reflection grating by coating a nine-layer quarter-wave system of ZnS/Na3AlF6 directly onto a surface-relief grating in photoresist. Efficiencies of 70% and 84% were measured at the first-order Littrow mount with the laser beam incident from the air side and from the substrate side, respectively. The experimental results are in qualitative agreement with theoretical predictions. The key to further improvement in the diffraction efficiency is to improve the contour conformation of the coated dielectric layers.

All-dielectric high-efficiency reflection gratings made with multilayer thin-film coatings

An electrostrictive micro-pump is provided for controlling a fluid flow through a cannula or other narrow liquid conduit. The micro-pump includes a pump body having a passageway for conducting a flow of fluid, a pump element formed from a piece of viscoelastic material and disposed in the passageway, and a control assembly coupled to the viscoelastic material for electrostatically inducing a peristaltic wave along the longitudinal axis of the pump element to displace fluid disposed within the pump body. The control assembly includes a pair of electrodes disposed over upper and lower sides of the pump element. The lower electrode is formed from a plurality of uniformly spaced conductive panels, while the upper electrode is a single sheet of conductive material. A switching circuit is provided for actuating the conductive panels of the lower electrode in serial, multiplex fashion to induce a peristaltic pumping action.

Electrostrictive micro-pump

A mandrel for forming a nozzle plate having orifices of precise size and location, and method of making the mandrel. The nozzle plate is formed by overcoating a substrate with a metal film. The film is covered with a photoresist material. Portions of the photoresist are exposed to light passing through a photomask having an annular light-transparent regions, of precise diameters and pitch. The photoresist is subjected to a developer bath which dissolves the photoresist exposed to the light, thereby revealing selected portion of the film. Next, an etchant is brought into contact with the film for etching-away the film so as to an annular opening in the film defining a column of precise diameter at the center of each opening. A new photoresist layer is then applied to the film. Portions of the new photoresist layer is exposed to light passing through a second photomask. The new photoresist material is then subjected to the developer which dissolves the new photoresist material to reveal the film beneath the photoresist and selected areas of the substrate. A second etchant is applied to create an annular recess extending into the substrate. The column resides at the center of the recess. This forms the nozzle plate mandrel. Next, a metal layer that will form the nozzle plate is deposited onto the film and grows into the recess to substantially fill the recess, except for the space occupied by the column. The finished nozzle plate is separated from the film/substrate structure to obtain orifices with precise diameters and pitch.

Mandrel for forming a nozzle plate having orifices of precise size and location and method of making the mandrel

In a method for forming lenslets which collect light and focus it onto photosensitive elements of an electronic imager includes providing a transparent lenslet-forming layer on a substrate or on layers on the substrate, (a) providing a transparent polyester lenslet-forming layer on a substrate or on layer(s) on the substrate, the polyester containing repeat units, in part, having the structure ##STR1## wherein: n is 2 or greater; x is selected from the group consisting of H, CH 3 , Br and Cl; and Z is selected from the group consisting of nil, O, S, CH 2 , C═O, SO, SO 2 , CH--CH 3 , CH 3 --C--CH 3 , CF 3 --C--CF 3 , CH 3 --C--CH 2 CH 3 , ##STR2## (b) forming a thin etch-stop layer on the transparent lenslet-forming layer and patterning the etch-stop layer to form a mask so that the pattern corresponds to lenslets to be formed; (c) anisotropically plasma etching the transparent lenslet-forming layer according to the pattern; (d) removing the thin etch-stop mask; and (e) thermally reflowing the patterned transparent layer to form the transparent lenslets

Jeffrey I. Hirsh

Papers

Pattern transfer techniques for fabrication of lenslet arrays for solid state imagers

All-dielectric high-efficiency reflection gratings made with multilayer thin-film coatings

Electrostrictive micro-pump

Mandrel for forming a nozzle plate having orifices of precise size and location and method of making the mandrel

Pattern transfer techniques for fabrication of lenslet arrays using specialized polyesters