BACKGROUND

This specification relates to miniature electrostatic motors and micro force transfer devices such as gears and gear trains.

An electric motor is a machine that converts electrical energy into mechanical energy. There are various types of electric motors as well as various fabrication techniques and technologies used to construct such motors. Selection of both a motor type and a fabrication technology are driven by performance, application suitability and cost considerations. Most electric motors include a stator (stationary element that has a magnetic field) and a rotor that rotates and has conductors that carry currents. The motor operates through an interaction between the motor's magnetic field and the currents generated in the conductors of the rotor.

Another type of electric motor is an electrostatic motor. Electrostatic motors operate using capacitive effects based on attraction and repulsion of electric charges.

Force transfer through gears and such devices is well-known. A gear is a machine part that has teeth cut into the part that can interact with corresponding teeth in another machine part to transmit torque from a driven gear to a drove gear. A set of geared devices can change the speed, torque, and/or direction of a source of force. A set of two or more gears can provide a change in torque. The teeth on two meshing gears that have the same shape and working in a sequence are referred to as a gear train. If one gear of the gear train is larger than the other, the rotational speeds and the torques of the two gears will differ in proportion to the diameters of the gears.

Various techniques and technologies have been used to produce gears according to performance, application suitability and cost considerations.

SUMMARY

According to an aspect, a micro mechanical force transfer device, includes a body comprising a body frame, the body frame defining a chamber and at least one gear element, the gear element comprising a central region, a membrane affixed to a surface of the body frame, the membrane covering the chamber, the membrane having an annular aperture in a region of the membrane over the central region, with the annular aperture defining a central region of the membrane, which central region of the membrane affixed to the central region of the gear element.

The above aspect may include amongst other features one or more of the following features:

The micro mechanical force transfer device wherein at least one gear element is connected to a shaft. The micro mechanical force transfer device wherein the shaft is provided by the portion of the membrane layer enclosed by the annular aperture. The micro mechanical force transfer device wherein at least one gear element is disposed about an axle. The micro mechanical force transfer device wherein the central region is physically spaced from the at least one gear element, which central region provides an axle. The micro mechanical force transfer device wherein the annular aperture over the central region is a first annular aperture, the membrane further having a second annular aperture in a region of the membrane spaced from the first annular aperture, with the first and second annular apertures defining a region of the membrane that is affixed to an annular region around the central region of the gear element to provide the axle.

The micro mechanical force transfer device of further includes a gear support layer affixed to an opposing surface of the membrane. The micro mechanical force transfer device wherein the gear support layer, further includes a second body comprising a body frame, the body frame defining a chamber and at least one gear support element, the gear support element having features corresponding in size and extent to features of the gear. The micro mechanical force transfer device of further includes a second membrane affixed to the gear body, the second membrane having a first annular aperture in a region of the second membrane over the central region of the at least one gear element, with the annular aperture defining a central region of the second membrane that is affixed to the central region of the at least one gear element to provide a shaft on the second membrane. The micro mechanical force transfer device further includes a second membrane affixed to the gear body, the second membrane having a first annular aperture in a region of the second membrane over the central region of the at least one gear element, with the annular aperture defining a central region of the second membrane that is affixed to the central region of the at least one gear element, and having a second annular aperture in a region of the second membrane spaced from the first annular aperture, with the first and second annular apertures defining a region of the second membrane that is affixed to an annular region around the central region of the gear element.

The micro mechanical force transfer device wherein the membrane is a first membrane and the micro mechanical force transfer device further includes a second membrane layer affixed to an opposing surface of the body frame. The micro mechanical force transfer device further includes a second gear element within the chamber defined in the body frame that is intermeshed with the first gear element in the body frame. The micro mechanical force transfer device wherein the body frame, the membrane, and the gear element are a first body frame, a first membrane, and a first gear element respectively, the device further includes a second body defining a second body frame defining a chamber and a second gear element, and a second membrane on a first surface of the second body covering the chamber.

The micro mechanical force transfer device wherein the gear element is a first gear element and the device further comprises a second gear element, with each of the first gear and the second gear elements are comprised of the same material as the body frame and each of the first and second gear elements has gear teeth, with the gear teeth of the first gear element intermeshed with the gear teeth of the second gear element.

The micro mechanical force transfer device wherein the first and second gears are in a first body layer and each are coupled to a narrow collar portion about an axle, which collar is at a second body layer. The micro mechanical force transfer device wherein the body having the at least one gear element and the membrane comprise a first stage and the device further includes a plurality of additional stages of bodies and membranes, with at least some of the stages having a height in a range of 25 microns to 250 microns. The micro mechanical force transfer device further comprising a driver stage. The micro mechanical force transfer device wherein the driver stage includes a motor. The micro mechanical force transfer device of wherein the motor is an micro-electrostatic motor. The micro mechanical force transfer device further including an output stage that includes a platen.

According to an aspect, a method of manufacturing a micro mechanical force transfer device, method includes patterning a sheet of a flexible material having a major surface with a layer of an adhesive, to define from the sheet, a body having body walls that define a chamber and at least one gear element tethered to portions of the body, a central portion of the at least one gear element, and to provide the adhesive on surfaces of the body walls and the central portion, providing a membrane on the body walls and covering the chamber, with the membrane adhered to the body walls and the central portion, forming an annular aperture that encloses a portion of the membrane that is affixed to the central element.

The above aspect may include amongst other features one or more of the following features:

The method wherein at least one gear element is connected to a shaft. The method wherein the portion of the membrane layer enclosed by the annular aperture, which is affixed to the central region provides the shaft. The method wherein at least one gear element is disposed about an axle. The method wherein patterning the sheet further includes patterning the sheet to provide the central region physically spaced from remaining portions of the at least one gear element. The method wherein the annular aperture is a first annular aperture, the membrane further having a second annular aperture in a region of the membrane spaced from the first annular aperture, with the first and second annular apertures defining a region of the membrane that is affixed to an annular region around the central region of the gear element to provide the axle. The method further includes patterning a second body layer to form a gear support element, and affixing the patterned second body layer having the gear support element to an opposing surface of the membrane. The method wherein the second body is further patterned to define a body frame defining a chamber and at least one gear support element, the gear support element having features corresponding in size and extent to features of the gear element. The method further includes affixing a second membrane to the gear body and patterning the second membrane to define a first annular aperture in a region of the second membrane over the central region of the at least one gear element, with the annular aperture defining a central region of the second membrane that is affixed to the central region of the at least one gear element to provide a shaft on the second membrane. The method further includes affixing a second membrane to the gear body, and patterning the second membrane to define a first annular aperture in a region of the second membrane over the central region of the at least one gear element, with the first annular aperture defining a central region of the second membrane that is affixed to the central region of the at least one gear element and a second annular aperture in a region of the second membrane spaced from the first annular aperture, with the first and second annular apertures defining a region of the second membrane that is affixed to an annular region around the central region of the gear element.

According to an aspect, an arrangement includes a micro mechanical force transfer device, includes a first body comprising a first body frame, the first body frame defining a first chamber and at least one gear element, the gear element comprising a central gear element region, a first membrane affixed to a surface of the first body frame, the membrane covering the chamber and having an annular aperture enclosing a central region of the membrane that is affixed to the central gear element region of the gear element, a micro electrostatic motor includes a second body having a first and a second face, the second body defining a second chamber and a rotor having a central region, a second membrane over the first face of the second body, the second membrane supporting a pair of spaced electrodes that are electrically isolated by a gap, the second membrane having an annular aperture that defines a central region of the membrane that is coupled to the central region of the rotor.

The above aspect may include amongst other features one or more of the following features:

The arrangement wherein the rotor is comprise of a disk of material of the second body that is disposed in the second chamber, physically spaced from an interior wall of the chamber, the disk having on a first surface thereof a set of three mutually electrically isolated electrodes, with each of the electrodes having a tab portion and being electrically isolated from the central member. The arrangement wherein a shaft is provided by the portion of the membrane layer enclosed by the annular aperture in the second membrane. The arrangement wherein an axle is provided by the portion of the second membrane layer enclosed by the annular aperture, and with the rotor and a central region of the rotor being physically isolated. The arrangement wherein the annular aperture in the second membrane is a first annular aperture, the second membrane further having a second annular aperture in a region of the second membrane spaced from the first annular aperture, with the first and second annular apertures defining a region of the second membrane that is affixed to the rotor to provide the axle.

The gear train (force transfer) devices described below can be made using micro fabrication methods and can be used either with a high speed, low torque electrostatic motor or a low speed high torque electrostatic motor for a variety of industrial, medical, and biological applications. The gear train devices are fabricated using relatively inexpensive techniques. In particular embodiments, the gear train devices described below are fabricated using roll to roll manufacturing techniques. In addition, a variety of industrial, medical, and biological applications may use the gear train (force transfer) devices with other devices besides a motor or can be used without other devices.

The micro electrostatic motor described below can be made using micro fabrication methods and can be used either as a high speed, low torque motor or a low speed high torque motor for a variety of industrial, medical, and biological applications. The micro electrostatic motor devices described below are fabricated using relatively inexpensive techniques. In particular embodiments, the micro electrostatic motor devices described below are fabricated using roll to roll manufacturing techniques.

The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention are apparent from the description and drawings, and from the claims.

