The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform
Suwas Nikumb - One of the best experts on this subject based on the ideXlab platform.
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Polymer micromolds with near optical quality surface finishes
Microfluidics BioMEMS and Medical Microsystems X, 2012Co-Authors: Pun-pang Shiu, George K. Knopf, Suwas NikumbAbstract:Disposable microfluidic systems are used to avoid sample contamination in a variety of medical and environmental monitoring applications. A contactless hot intrusion (HI) process for fabricating reusable polymer micromolds with near "optical quality" surface finishes is described in this paper. A metallic hot intrusion mask with the desired microchannels and related passive components is first machined using a tightly focused beam from a diode-pumped solid-state (DPSS) laser. The polymer mold master is then created by pressing the 2D metallic mask onto a polymethylmethacrylate (PMMA) substrate. Since it is a contactless fabrication process the resultant 3D micro-reliefs have near optical quality surface finishes. Unfortunately, the desired micro-relief dimensions (height and width) are not easily related to the hot intrusion process parameters of pressure, temperature, and time exposure profile. A finite element model is introduced to assist the Manufacturing Engineer in predicting the behavior of the PMMA substrate material as it deforms under heat and pressure during micromold manufacture. The FEM model assumes that thermo-plastics like PMMA become "rubber like" when heated to a temperature slightly above the glass transition temperature. By controlling the material temperature and maintaining its malleable state, it is possible to use the stress-strain relationship to predict the profile dimensions of the imprinted microfeature. Examples of curved microchannels fabricated using PMMA mold masters are presented to illustrate the proposed methodology and verify the finite element model. In addition, the non-contact formation of the micro-reliefs simplifies the demolding process and helps to preserve the high quality surface finishes.
Nikumb S. - One of the best experts on this subject based on the ideXlab platform.
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Polymer micromolds with near optical quality surface finishes
2012Co-Authors: Shiu P.-p., Knopf G.k., Nikumb S.Abstract:Disposable microfluidic systems are used to avoid sample contamination in a variety of medical and environmental monitoring applications. A contactless hot intrusion (HI) process for fabricating reusable polymer micromolds with near "optical quality" surface finishes is described in this paper. A metallic hot intrusion mask with the desired microchannels and related passive components is first machined using a tightly focused beam from a diode-pumped solid-state (DPSS) laser. The polymer mold master is then created by pressing the 2D metallic mask onto a polymethylmethacrylate (PMMA) substrate. Since it is a contactless fabrication process the resultant 3D micro-reliefs have near optical quality surface finishes. Unfortunately, the desired micro-relief dimensions (height and width) are not easily related to the hot intrusion process parameters of pressure, temperature, and time exposure profile. A finite element model is introduced to assist the Manufacturing Engineer in predicting the behavior of the PMMA substrate material as it deforms under heat and pressure during micromold manufacture. The FEM model assumes that thermo-plastics like PMMA become "rubber like" when heated to a temperature slightly above the glass transition temperature. By controlling the material temperature and maintaining its malleable state, it is possible to use the stress-strain relationship to predict the profile dimensions of the imprinted microfeature. Examples of curved microchannels fabricated using PMMA mold masters are presented to illustrate the proposed methodology and verify the finite element model. In addition, the non-contact formation of the micro-reliefs simplifies the demolding process and helps to preserve the high quality surface finishes. \ua9 2012 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).Peer reviewed: YesNRC publication: Ye
Liu Hongli - One of the best experts on this subject based on the ideXlab platform.
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Research on Post Processing Technique of CAXA Manufacturing Engineer based on FANUC System
New Technology & New Process, 2010Co-Authors: Liu HongliAbstract:In this paper,based on the practical experience of computer-aided Manufacturing in the CAD/CAM practical training center in Xi'an railway vocational and technical college,the imperfection in the use of the "post-processing for CAXA Manufacturing Engineer" was analyzed and summarized. The general mode that applied on the FANUC CNC system by using the text editing software was brought out,and this mode can improve the CNC programming efficiency greatly.
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Study on the Post Processing Technology of CAXA Manufacturing Engineer
New Technology & New Process, 2009Co-Authors: Liu HongliAbstract:This paper analyses and sums up the imperfection during the use of the "post-processing of CAXA Manufacturing Engineer",based on the practical experience of computer-aided Manufacturing in the CAD/CAM practical training center of Xi'an Railway Vocational Technical College. And then this paper puts forward the general establishment pattern for Siemens CNC system,by the help of text editing software,and this pattern can improve the efficiency of CNC programming.
Donald W. Duritsch - One of the best experts on this subject based on the ideXlab platform.
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Getting Started in Technology Transfer: Experiences from the Ohio Technology Transfer Organization
Industry and higher education, 1992Co-Authors: Donald W. DuritschAbstract:In December 1991, Donald Duritsch accepted a position to initiate and operate a technology transfer office at a major US university. After more than thirty years in private industry holding positions ranging from Manufacturing Engineer to chief Engineer to director of operations, he was motivated to cross to the academic sector by the challenge of assisting small manufacturers to become more productive and profitable. In this article, he describes the resources available to manufacturers in Ohio and relates the experiences of a new technology transfer agent during his first six months of operation. Finally, Mr Duritsch provides a short commentary on the keys to success in initiating and developing technology transfer.
D. B. Lewis - One of the best experts on this subject based on the ideXlab platform.
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Optimizing the performance of high speed steel circular saw blades machining cupro 107, Inconel 600L and Nimonic PK31 nickel based alloys
Journal of Materials Science, 1996Co-Authors: M. Sarwar, S. R. Bradbury, D. B. LewisAbstract:Nickel based alloys are machined by methods similar to those used to cut ferrous materials, however there are additional process requirements due to the poor machinability of these alloys. The current paper reports on work undertaken to optimize the cutting conditions for high speed steel circular saw blades machining materials from three of the principal categories of nickel based alloy. Techniques have been developed and verified that simulate the cutting characteristics of multi-point cutting tools by testing blade segments that contain representative teeth. The cutting behaviour of high speed steel circular saw blades have been simulated in this manner. Materials from three of the principal classifications of nickel based alloy; Cupro 107, Inconel 600L and Nimonic PK31, have been machined over a range of cutting feeds and speeds. Cutting and thrust forces were measured and the performance criteria, specific cutting energy (Esp) evaluated. Optimized cutting conditions for each material were determined from curves of Esp against feed rate at the selected cutting speeds. In an area of high product and material costs, the information contained within this paper will be of interest to the Manufacturing Engineer and end user when appraising the suitability of high speed steel circular saw blades as a tool for machining these materials.