Texas Instruments Corporation

Nathan Brockie

William David French

Roozbeh Parsa

Terry Dyer

Ann Gabrys

Iouri N Mirgorodski

Terrence Edward Dyer

An integrated microfabricated sensor includes a sensor cell having a cell body, a first window attached to the cell body, and a second window attached to the cell body. The cell body laterally surrounds a cavity, so that both windows are exposed to the cavity. The sensor cell contains a sensor fluid material in the cavity. The cavity has concave profiles at cell body walls, so that the cavity is wider in a central region, approximately midway between the first window and the second window, than at the first surface and at the second surface. The cell body walls of the cell body have acute interior angles at both windows. The cell body is formed using an etch process that removes material from the cell body concurrently at the first surface and the second surface, forming the acute interior angles at both the first surface and the second surface.

Concave cavity for integrated microfabricated sensor

An integrated microfabricated sensor includes a sensor cell having a cell body, a first window attached to a first surface, and a second window attached to a second surface, opposite to the first window. The cell body laterally surrounds a cavity, so that the first window and the second window are exposed to the cavity. The sensor cell contains a sensor fluid material in the cavity. The cell body has recesses on opposing exterior sides of the cell body; each recess extends from the first surface to the second surface. Exterior portions of the cell body wall in the recesses are recessed from singulation surfaces on the cell body exterior. The cell body is formed by etching the cavity and the recesses concurrently through a body substrate. After the windows are attached, the sensor cell is singulated from the body substrate through the recesses.

Microfabricated atomic clocks and magnetometers utilizing side recesses

A microfabricated sensor includes a sensor cell with a cell body and a window attached to the cell body. A sensor cavity containing sensor fluid material is located in cell body, open to the window. A signal path extends from a signal emitter outside the sensor cell, through the window and sensor cavity, and to a signal detector. The sensor cell may have an asymmetric thermal configuration, conducive to developing a temperature gradient in the sensor cell. One or more heaters are disposed on the sensor cell, possibly in an asymmetric configuration. Power is applied to the heaters, possibly asymmetrically, so as to develop a temperature gradient in the sensor cell with a low temperature region in the sensor cell, sufficient to condense the sensor fluid in the low temperature region, outside of the signal path.

Temperature gradient in microfabricated sensor cavity

A sensor cell has a chamber that defines an internal sensor volume for a sensor fluid in a vapor phase. A signal path extends into the internal sensor volume. The sensor cell includes a condensation reservoir for a condensed phase of the sensor fluid, in fluid communication with the internal sensor volume. The signal path is spatially separate from the condensation reservoir. During operation of the sensor cell, some of the sensor fluid may be converted to a vapor phase in the internal sensor volume. During such operation, sensor fluid in the condensed phase is disposed in the condensation reservoir, advantageously out of the signal path, leaving the signal path desirably free of the condensed phase sensor fluid. During periods of non-operation, a significant portion of the sensor fluid may condense from the vapor phase to the condensed phase in the condensation reservoir, advantageously out of the signal path.

Sensor fluid reservoirs for microfabricated sensor cells

Vapor cells and methods for making the same are presented, in which a cell cavity is completely filled with aqueous alkali metal azide solution and the solution is dried at a controlled evaporation rate to substantially maintain edge contact pinning at an interface with the cavity sidewall to promote preferential evaporation in the center and outward capillary flow from an unpinned air-fluid interface toward the sidewall to form crystallized alkali metal material at the sidewall while inhibiting drying of dispersed aqueous solution on a transparent cavity bottom to provide substantially unrestricted passage of light through the cavity for atomic clock and other applications.

Growing community of inventors

Edinburgh, United Kingdom

Nathan Brockie