Education

Research Description

Dr. Dow's long-term goal is to improve how we make and measure devices that require tolerances of 1 part in 105 of the feature size to operate correctly. This means for a telescope measuring 1.5 meters (like the Hubbel Telescope), the shape tolerance is 15 micrometers.

Publications

Optics of balloon experimental twin telescope for infrared interferometry (BETTII): delay lines and alignment

Dhabal, A., Rinehart, S. A., Rizzo, M. J., Mundy, L., Fixsen, D., Sampler, H., Mentzell, E., Veach, T., Silverberg, R. F., Furst, S., Dow, T., Ade, P., & Tucker, C. (2016), In Optical and infrared interferometry and imaging v. (Proceedings of SPIE-the International Society for Optical Engineering, 9907).

Design and validation of the mounting structure for BETTII balloon-based telescope with thin-walled optics

Furst, S., Dow, T., Garrard, K., Sohn, A., Fixsen, D., Rinehart, S., Mentzell, E., Veach, T., Rizzo, M., & Dhabal, A. (2016), Journal of Astronomical Telescopes Instruments and Systems, 2(2).

Design of elliptically-vibrating ultrasonic actuator for nanocoining

Dow, T. A., Nowak, J., & Kessing, J. R. (2016), Precision Engineering, 45, 301-310.

Nanostructure fabrication on germanium and silicon by nanocoining imprint technique

Zdanowicz, E., Dow, T. A., Scattergood, R. O., & Youssef, K. (2013), Precision Engineering, 37(4), 871-879.

Thermo-chemical wear model and worn tool shapes for single-crystal diamond tools cutting steel

Lane, B. M., Dow, T. A., & Scattergood, R. (2013), Wear, 300(1-2), 216-224.

Rapid fabrication of nanostructured surfaces using nanocoining

Zdanowicz, E., Dow, T. A., & Scattergood, R. O. (2012), Nanotechnology, 23(41).

Design, modeling, fabrication, and evaluation of the air amplifier for improved detection of biomolecules by electrospray ionization mass spectrometry

Robichaud, G., Dixon, R. B., Potturi, A. S., Cassidy, D., Edwards, J. R., Sohn, A., Dow, T. A., & Muddiman, D. C. (2011), International Journal of Mass Spectrometry, 300(2-3), 99-107.

Diamond tool wear measurement by electron-beam-induced deposition

Shi, M., Lane, B., Mooney, C. B., Dow, T. A., & Scattergood, R. O. (2010), Precision Engineering, 34(4), 718-721.

Diamond tool wear when machining Al6061 and 1215 steel

Lane, B. M., Shi, M., Dow, T. A., & Scattergood, R. (2010), Wear, 268(11-12), 1434-1441.

Automated part centering with impulse actuation

Furst, S. J., Dow, T. A., Garrard, K., & Sohn, A. (2010), Journal of Manufacturing Science and Engineering, 132(1).

View all publications via NC State Libraries

Grants

Membership in PE Consortium, Full Member

Oculus(1/01/17 - 12/31/18)

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Membership in PE Consortium, Full Member

Sponsor: Oculus

Start Date: 1/01/17

End Date: 12/31/18

Abstract

This Agreement is made by and between North Carolina State University at Raleigh, North Carolina and Oculus. The parties to this Agreement intend to join together in a cooperative effort to support a University/Industry Precision Engineering Center at UNIVERSITY such that the UNIVERSITY environment can be used to develop a better understanding of Precision Engineering, stimulate industrial innovation; and provide UNIVERSITY with strengthened educational capability in these fields, and MEMBER with the latest advances in technology.

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PEC Double Membership - Full Member

Los Alamos National Laboratory(1/01/16 - 12/31/16)

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PEC Double Membership - Full Member

Sponsor: Los Alamos National Laboratory

Start Date: 1/01/16

End Date: 12/31/16

Abstract

This Agreement is made by and between North Carolina State University at Raleigh, North Carolina and Los Alamos National Laboratories. The parties to this Agreement intend to join together in a cooperative effort to support a University/Industry Precision Engineering Center at UNIVERSITY such that the UNIVERSITY environment can be used to develop a better understanding of Precision Engineering, stimulate industrial innovation; and provide UNIVERSITY with strengthened educational capability in these fields, and MEMBER with the latest advances in technology.

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Design, Develop and Fabricate Primary and Siderostat Mirrors for BETTII Telescope

National Aeronautics & Space Administration (NASA)(6/04/15 - 5/31/16)

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Design, Develop and Fabricate Primary and Siderostat Mirrors for BETTII Telescope

Sponsor: National Aeronautics & Space Administration (NASA)

Start Date: 6/04/15

End Date: 5/31/16

Abstract

This proposal describes the research and development efforts needed to create high quality mirror surfaces on the rough machined and heat treated parabolic primary mirrors that are to be delivered to the PEC in May and assist in the design and fabrication of the two flat siderostat mirrors on the main frame of the telescope. a. The two primary mirrors are off-axis conic surfaces and to machine them on-axis is a complex process requiring the tool to follow a non-rotationally symmetric path to create the desired shape. The unique facilities at the PEC were designed for this type of fabrication. The cost of this phase of the proposed project will cost $61,535. b. The second phase of this proposal is to assist in the design and fabrication of the large flat siderostat mirrors used to direct the star(s) of interest onto the primary telescope mirrors. The details of machining the Siderostats is being proposed by the PEC. An estimate of the cost to modify the design and final machine the 2 Siderostats is $47,583. The total cost of the project is $109,118.

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Ultra-sonic Nano-coining for Creating Large Anti-reflective Surfaces

National Science Foundation (NSF)(7/01/15 - 12/30/16)

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Ultra-sonic Nano-coining for Creating Large Anti-reflective Surfaces

Sponsor: National Science Foundation (NSF)

Start Date: 7/01/15

End Date: 12/30/16

Abstract

ULTRA-SONIC NANO-COINING FOR CREATING LARGE ANTI-REFLECTIVE SURFACES NC State University Precision Engineering Center (sub-award) Statement of Work The team at the NC State University Precision Engineering Center (PEC), led by Dr. Thomas Dow (Co-PI), will lead the effort to fabricate 5 diamond dies by FIB machining. The FIB machining will be done in conjunction with the Analytical Instrumentation Facility (AIF) at NC State. The diamond dies will consist of a 20x20 μm array of 200 nm wide, 100 nm deep features. The features will be placed on the end of a 1x1x5 mm diamond blank that has been down to 20x20 μm on one end. Dr. Dow and PEC Senior Researcher Ken Garrard will also assist in the design of an improved actuator alignment fixture and force-feedback concept for touch-off and depth control. Mr. Garrard will use his expertise in computer programming and data acquisition to develop a functional user interface that tracks the diamond turning machine position as well as the state of the actuator and alignment stages. Daily interaction will be needed while the actuator is integrated into the PEC’s Nanoform 600 diamond turning machine (DTM). This machine will be rented to Smart Material Solutions, LLC for 180 hrs at the standard rate of $75/hr. Furthermore, once test parts and replicated surfaces are created, Dr. Dow will lead the effort to conduct surface metrology. The surfaces will be measured with the PEC’s Zygo Nuview white light interferometer and with the AIF’s scanning electron microscope (SEM) and atomic force microscope (AFM). Use rate for the PEC’s metrology equipment for 40 hrs at a rate of $75/hr is included in the NCSU sub-award. Use of AIF’s FIB machine center, SEM, and AFM as well as staff time is listed in the NCSU sub-award. The expected effort from AIF is 300 hrs at the NCSU internal rate of $100/hr. Finally, Dr. Dow will leverage his extensive network of industry leaders to establish contact between Smart Material Solutions, LLC and a partner for roll-to-roll scale-up. Dr. Dow will assist in the effort to establish a specific plan to indent an industrial roll in phase 2.

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PEC Membership, Patron Member

Johnson & Johnson Vision Care, Inc (formerly Vistakon)(1/01/15 - 12/31/17)

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PEC Membership, Patron Member

Sponsor: Johnson & Johnson Vision Care, Inc (formerly Vistakon)

Start Date: 1/01/15

End Date: 12/31/17

Abstract

This Agreement is made by and between North Carolina State University at Raleigh, North Carolina and J&J Vision Care. The parties to this Agreement intend to join together in a cooperative effort to support a University/Industry Precision Engineering Center at UNIVERSITY such that the UNIVERSITY environment can be used to develop a better understanding of Precision Engineering, stimulate industrial innovation; and provide UNIVERSITY with strengthened educational capability in these fields, and MEMBER with the latest advances in technology.

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Design and Fabrication of Bettii Telescope Mirror Assemblies

National Aeronautics & Space Administration (NASA)(6/30/14 - 6/30/15)

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Design and Fabrication of Bettii Telescope Mirror Assemblies

Sponsor: National Aeronautics & Space Administration (NASA)

Start Date: 6/30/14

End Date: 6/30/15

Abstract

The focus of this project is the design and fabrication of the primary mirrors and mounting assemblies for the BETTII balloon-based telescope. The two main mirrors are approximately 600 mm in diameter and are sections of an off-axis parabola. The current design hangs the secondary mirror from struts attached to the primary and this is causing excessive distortion of the primary. Phase I will involve a redesign of the mirror support system to reduce the gravitational deflection of the primary mirror and minimize alignment and assembly time. Phase I will also include an estimate for the cost of fabricating and delivering the two mirror assemblies. This project will require close interaction between the staff at NASA Goddard and the PEC and will involve at least one design review at Goddard. Phase II will involve the development of techniques to fabricate these large non-rotationally symmetric optical surfaces and the structure that supports/aligns the 4 mirrors on each telescope. This phase will be to create 2 assemblies each of which contains a primary and turning mirror and the structure that supports and aligns these mirrors.

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Design and Fabrication of Bettii Telescope Mirror

National Aeronautics & Space Administration (NASA)(11/18/13 - 12/31/14)

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Design and Fabrication of Bettii Telescope Mirror

Sponsor: National Aeronautics & Space Administration (NASA)

Start Date: 11/18/13

End Date: 12/31/14

Abstract

The focus of this project is the design and fabrication of the primary mirrors and mounting assemblies for the BETTII balloon-based telescope. The two main mirrors are approximately 600 mm in diameter and are sections of an off-axis parabola. The current design hangs the secondary mirror from struts attached to the primary and this is causing excessive distortion of the primary. Phase I will involve a redesign of the mirror support system to reduce the gravitational deflection of the primary mirror and minimize alignment and assembly time. Phase I will also include an estimate for the cost of fabricating and delivering the two mirror assemblies. This project will require close interaction between the staff at NASA Goddard and the PEC and will involve at least one design review at Goddard.

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PEC Membership - St Gobain- Patron

Saint-Gobain Abrasives, Inc.(1/01/13 - 12/31/15)

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PEC Membership - St Gobain- Patron

Sponsor: Saint-Gobain Abrasives, Inc.

Start Date: 1/01/13

End Date: 12/31/15

Abstract

This Agreement is made by and between North Carolina State University at Raleigh, North Carolina and St Gobain Abrasives. The parties to this Agreement intend to join together in a cooperative effort to support a University/Industry Precision Engineering Center at UNIVERSITY such that the UNIVERSITY environment can be used to develop a better understanding of Precision Engineering, stimulate industrial innovation; and provide UNIVERSITY with strengthened educational capability in these fields, and MEMBER with the latest advances in technology.

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Polaris3D Upgrades and Measurement Capability Enhancements

Johnson & Johnson Vision Care, Inc (formerly Vistakon)(6/05/13 - 1/31/14)

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Polaris3D Upgrades and Measurement Capability Enhancements

Sponsor: Johnson & Johnson Vision Care, Inc (formerly Vistakon)

Start Date: 6/05/13

End Date: 1/31/14

Abstract

The objective of this proposed project is to enhance the capabilities and performance of the Polaris3D spherical coordinate measuring machine. Enhancements include compensation of repeatable error motions of the spindle and rotary table and implementation of a robust probe triggering algorithm. Issues with measurements of cylinder diameters will also be addressed.

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Investigating Grit Design and Material on Grinding Forces, Wear and Temperature

Saint-Gobain Abrasives, Inc.(1/01/13 - 7/31/15)

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Investigating Grit Design and Material on Grinding Forces, Wear and Temperature

Sponsor: Saint-Gobain Abrasives, Inc.

Start Date: 1/01/13

End Date: 7/31/15

Abstract

for continued work at St Gobain.The goal of this project is to assist St. Gobain in the creation of new grinding grits by providing methods to measure the forces, chip geometry, tool temperature and wear during the grinding process as well as models to predict and extrapolate grit performance. These parameters will be related to measurable grit parameters such as shape, hardness, structure, etc. As these experimental techniques are created and a theoretical foundation is established, close contact between faculty, staff and students at NC State with researchers at St. Gobain will be required to transfer the results. The work will begin on a general purpose diamond turning machine with a diamond tool as the initial grit. Preliminary experiments will establish the relationship among the tool shape, wear and forces based on the operating conditions, a diamond tool and several different workpiece materials. Models of the tool temperature will be created to relate the measured tool wear to current models of wear vs. temperature and experiments will be performed to measure the peak temperature at the tool edge. These initial tests will lead to experiments using actual grinding ?grits? and the process will be repeated with appropriate modifications to the system. Based on the results, specific equipment needed at St. Gobain will be defined and a new fixture will be designed and built with funding outside this proposed project. The results of this research will be presented as a function of the surface speed, depth of cut, grit shape and workpiece/tool materials including: ? Models and measurements for grit temperature, ? Measurements and models of tool forces, ? Measured grit wear and wear from a grit wear model, and ? Design of fixture

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