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Full-Text Articles in Mechanical Engineering

Surface Acoustic Wave Based Pumping In A Microchannel, Tao Wang, Qi Ni, Nathan B. Crane, Rasim Guldiken May 2017

Surface Acoustic Wave Based Pumping In A Microchannel, Tao Wang, Qi Ni, Nathan B. Crane, Rasim Guldiken

Faculty Publications

Pumping and manipulation of liquids in microfluidic channels is important for many mechanical, chemical and biomedical applications. Surface acoustic wave based devices fabricated on high-efficiency piezoelectric substrates have been recently investigated for mixing and separation application within microfluidic channels. In this paper, we introduce a novel integrated surface acoustic wave based pump for liquid delivery and precise manipulation within a microchannel. The device employs a hydrophobic surface coating (Cytop) in the device design for decreasing the friction force and increasing the bonding. Contrary to previous surface acoustic wave based pump, this device does not need precise layers of water and …


Binder-Jet Printing Of Fine Stainless Steel Powder With Varied Final Density, Mohsen Ziaee, Eric M. Tridas, Nathan B. Crane Mar 2017

Binder-Jet Printing Of Fine Stainless Steel Powder With Varied Final Density, Mohsen Ziaee, Eric M. Tridas, Nathan B. Crane

Faculty Publications

Binder jetting is an additive manufacturing process that produces relatively weak porous parts that are strengthened through sintering and/or infiltration. This paper reports on two different methods of preparing fine 316 stainless steel powder and their impact on the final sintered density and dimensions relative to direct printing into -22 micron powder. The first method uses agglomerates of fine powder. In the second, nylon 12 powders are mixed with the steel powder as a fugitive space holder to increase porosity. Sintered density and sintering shrinkage of agglomerate material are shown to vary with the density of the spread powder bed. …


Controlled Manipulation Of Floating Objects On Deformed Fluid Interfaces And Conditions For Stable Equilibria, Jose M. Carballo, Qi Ni, Jose Vasquez, Nathan B. Crane Jan 2017

Controlled Manipulation Of Floating Objects On Deformed Fluid Interfaces And Conditions For Stable Equilibria, Jose M. Carballo, Qi Ni, Jose Vasquez, Nathan B. Crane

Faculty Publications

At the millimeter scale, interactions between floating and semi-immersed objects are significant. The local curvature of the interface is modified by the weight/buoyancy forces of floating objects, and by the surface properties of semi-immersed objects. The curvature changes generate attractive (or repulsive) interactions between floating parts, and semi-immersed objects. This work demonstrates how electrowetting can manipulate these interactions in order to position, align, assemble and transport parts attached to the fluid interface. This demonstrates one way in which fluid interfaces can provide an alternative to standard pick and place technology for part positioning/assembly. Typically, the part/rod forces are purely attractive …