Frank Peter

A Surface Micromachined Electrostatic Drop Ejector

Ejectors have applications ranging from ink-jet printing to drug delivery. A novel electrostatic ejector was surface micromachined; and satellite-free, 2 pl drops were ejected at 10 m/s using an electrostatic field (E-field) of 20 V/µm. The E-field is applied across the ejected liquid, which simplifies device design, but allows the possibility of dielectric breakdown and electrolysis in the liquid. These challenges were overcome in the prototype described herein.

The recodable locking device

The RLD performs two primary functions: code discrimination and energy switching. The RLD contains six decimal-encoded wheels creating a population of one million different codes. Since it is only stored in the mechanical device, discovery of the code is not possible through software operations. After the RLD verifies proper code entry, it mechanically actuates a switching element. The preferred implementation is an optical shutter blocking the path between an optical source and detector. Other implementations include electrical switch contacts and a pop-up mirror for routing optical energy. Fabrication Process Sandia’s surface silicon micromachining is a lithographic process using 11 mask levels to create four levels of polycrystalline silicon [1] (or polysilicon— the shorthand term). The process yields three movable levels of polysilicon in addition to a stationary level. The four-level polysilicon micromachining process enables the fabrication of articulated machinery with moving rotational joints and overlapping structures. Devices are created by alternately depositing a thin film, photolithographically patterning the film, and then performing chemical etching. By repeating this process with layers of silicon dioxide and polycrystalline silicon, complex three-dimensional shapes can be formed. The shapes themselves result from the fabrication process in conjunction with a series of twodimensional masks that define the patterns to be etched. In addition, a friction-reducing layer of silicon nitride is placed between the layers that form bearing surfaces. At the end of the fabrication process, the silicon dioxide is chemically removed, leaving behind

Autonomous gas chromatograph system for Thermal Enhanced Vapor Extraction System (TEVES) proof of concept demonstration

An autonomous gas chromatograph system was designed and built to support the Thermal Enhanced Vapor Extraction System (TEVES) demonstration. TEVES is a remediation demonstration that seeks to enhance an existing technology (vacuum extraction) by adding a new technology (soil heating). A pilot scale unit was set up at one of the organic waste disposal pits at the Sandia National Laboratories Chemical Waste Landfill (CWL) in Tech Area 3. The responsibility for engineering a major part of the process instrumentation for TEVES belonged to the Manufacturing Control Subsystems Department. The primary mission of the one-of-a-kind hardware/software system is to perform on-site gas sampling and analysis to quantify a variety of volatile organic compounds (VOCs) from various sources during TEVES operations. The secondary mission is to monitor a variety of TEVES process physical parameters such as extraction manifold temperature, pressure, humidity, and flow rate, and various subsurface pressures. The system began operation in September 1994 and was still in use on follow-on projects when this report was published.