12 Matching Results

Search Results

Advanced search parameters have been applied.

in creator/contributor: "McWhorter, P.J."

open access

Intricate Mechanisms-on-a Chip Enabled by 5-Level Surface Micromachining

Surface micromachining generally offers more design freedom than related technologies, and it is the technology of choice for most microelectromechanical applications that require multi-level structures. However, the design flexibility that surface micromachining offers is not without limitations. In addition to determining how to fabricate devices in a planar world, the designer also needs to consider issues such as film quality, thickness, residual stress, topography propagation, stringers, p… more

Date: March 30, 1999

Creator: Allen, J. J.; McWhorter, P. J.; Miller, S. L.; Rodgers, M. S.; Smith, J. H. & Sniegowski, J. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The Growing Necessity for Continuing Education: The Short Course Option

Continuing education is a critical issue in the workplace. Rapid change, the emergence of new technology, and the lack of trained individuals make continuing education an imperative for employers. The desire for individual growth and marketability make it an imperative for the employee also. While there are many options for continuing education, an increasingly popular vehicle is the short course. Time, cost efficiency and instruction by those experienced in real industrial practice are key fac… more

Date: February 2, 1999

Creator: McWhorter, P. J. & Romig, A. D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Hidden Challenges to MEMS Commercialization: Design Realization and Reliability Assurance

The successful commercialization of MicroElectroMechanical Systems (MEMS) is an essential prerequisite for their implementation in many critical government applications. Several unique challenges must be overcome to achieve this widespread commercialization. Challenges associated with design realization and reliability assurance are discussed, along with approaches taken by Sandia to successfully overcome these challenges.

Date: January 20, 1999

Creator: McWhorter, P. J.; Miller, S. L.; Miller, W. M.; Rodger, M. S. & Yarberry, V. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Microelectro-optical devices in a 5-level polysilicon surface micromachining technology

The authors recently reported on the development of a 5-level polysilicon surface micromachine fabrication process consisting of four levels of mechanical poly plus an electrical interconnect layer and its application to complex mechanical systems. This paper describes the application of this technology to create micro-optical systems-on-a-chip. These are demonstration systems, which show that five levels of polysilicon provide greater performance, reliability, and significantly increased funct… more

Date: August 1, 1998

Creator: Smith, J. H.; Rodgers, M. S.; Sniegowski, J. J.; Miller, S. L.; Hetherington, D.; McWhorter, P. J. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Advanced micromechanisms in a multi-level polysilicon technology

Quad-level polysilicon surface micromachining technology, comprising three mechanical levels plus an electrical interconnect layer, is giving rise to a new generation of micro-electromechanical devices and assemblies. Enhanced components can not be produced through greater flexibility in fabrication and design. New levels of design complexity that include multi-level gears, single-attempt locks, and optical elements have recently been realized. Extensive utilization of the fourth layer of polys… more

Date: August 1, 1997

Creator: Rodgers, M. S.; Sniegowski, J. J.; Miller, S. L.; Barron, C. C. & McWhorter, P. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Routes to failure in rotating MEMS devices experiencing sliding friction

Gear systems rotating on hubs have been operated to failure using Sandia`s microengine as the actuation device. Conventional failure modes such as fatigue induced fracture did not occur, indicating that the devices are mechanically extremely robust. The generic route to failure observed for all rotating devices involves sticking of structures that are in sliding contact. This sticking evidently results from microscopic changes in the sliding surfaces during operation. The rate at which these ch… more

Date: August 1, 1997

Creator: Miller, S. L.; LaVigne, G.; Rodgers, M. S.; Sniegowski, J. J.; Waters, J. P. & McWhorter, P. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Performance tradeoffs for a surface micromachined microengine

An electromechanical model of Sandia`s microengine is developed and applied to quantify critical performance tradeoffs. This is done by determining how forces impact the mechanical response of the engine to different electrical drive signals. To validate the theoretical results, model-based drive signals are used to operate actual engines, where controlled operation is achieved for the following cases: (1) spring forces are dominant, (2) frictional forces are dominant, (3) linear inertial force… more

Date: October 1, 1996

Creator: Miller, S. L.; Sniegowski, J. J.; LaVigne, G. & McWhorter, P. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Gas-driven microturbine

This paper describes an invention which relates to microtechnology and the fabrication process for developing microelectrical systems. It describes a means for fabricating a gas-driven microturbine capable of providing autonomous propulsion in which the rapidly moving gases are directed through a micromachined turbine to power devices by direct linkage or turbo-electric generators components in a domain ranging from tenths of micrometers to thousands of micrometers.

Date: June 27, 1996

Creator: Sniegowski, J. J.; Rodgers, M. S.; McWhorter, P. J.; Aeschliman, D. P. & Miller, W. M.

Item Type: Patent

Partner: UNT Libraries Government Documents Department

open access

Monolithic geared-mechanisms driven by a polysilicon surface-micromachined on-chip electrostatic microengine

We have previously described a practical micromachined power source: the polysilicon, surface-micromachined, electrostatically actuated microengine. Here we report on 3 aspects of implementing the microengine. First, we discuss demonstrations of the first-generation microengine actuating geared micromechanisms including gear trains with elements having dimensions comparable to the drive gear (about 50 {mu}m) and a relatively large (1600-{mu}m-diameter) rotating optical shutter element. These co… more

Date: May 1, 1996

Creator: Sniegowski, J. J.; Miller, S. L.; LaVigne, G. F.; Rodgers, M. S. & McWhorter, P. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Friction in surface micromachined microengines

Understanding the frictional properties of advanced Micro-Electro- Mechanical Systems (MEMS) is essential in order to develop optimized designs and fabrication processes, as well as to qualify devices for commercial applications. We develop and demonstrate a method to experimentally measure the forces associated with sliding friction of devices rotating on a hub. The method is demonstrated on the rotating output gear of the microengine recently developed at Sandia National Laboratories. In-situ… more

Date: March 1, 1996

Creator: Miller, S. L.; Sniegowski, J. J.; LaVigne, G. & McWhorter, P. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Dynamical modeling and characterization of a surface micromachined microengine

The practical implementation of the surface micromachined microengine [1,2] to perform useful microactuation tasks requires a thorough understanding of the dynamics of the engine. This understanding is necessary in order to create appropriate drive signals, and to experimentally measure fundamental quantities associated with the engine system. We have developed and applied a dynamical model of the microengine and used it to accomplish three objectives: (1) drive inertial loads in a controlled f… more

Date: January 1, 1996

Creator: Miller, S. L.; Sniegowski, J. J.; LaVigne, G. L. & McWhorter, P. J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Embedded micromechanical devices for the monolithic integration of MEMS and CMOS

No Description Available.

Date: July 1, 1995

Creator: Smith, J. H.; Montague, S.; Sniegowski, J. J. & McWhorter, P. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department