in this paper, the direct extrusion process of bimetallic rods in conical dies is analyzed by an improved upper bound method. the deformation zone is subdivided into six smaller zones and by considering a non-spherical entrance boundary to the deformation zone, a velocity field is presented which is different from velocity fields employed in previous studies. the total power consumption of the ...

Bimetallic nanorods are propelled without chemical fuels in megahertz (MHz) acoustic fields, and exhibit similar behaviors to single-metal rods, including autonomous axial propulsion and organization into spinning chains. Shape asymmetry determines the direction of axial movement of bimetallic rods when there is a small difference in density between the two metals. Movement toward the concave e...

In this paper, an upper bound approach is used to analyze the extrusion process of bimetallic rods through arbitrarily curved dies. Based on a spherical velocity field, internal, shearing and frictional power terms are calculated. The developed upper bound solution is used for calculating the extrusion force for two types of die shapes: a conical die as a linear die profile and a streamlined di...

Synthetic microswimmers offer models for cell motility and their tunability makes them promising candidates biomedical applications. Here we measure the acoustic propulsion of bimetallic micro-rods that, when trapped at nodal plane a MHz resonator, swim with speeds up to 300 microns per second. While past streaming predict that are more than one order magnitude smaller our measurements, demonst...

Effects of annealing treatment after equal channel angular pressing (ECAP) on the interface properties and shear bond strength of Al/Cu bimetallic rods were investigated. For the as-deformed samples, the one with two passes of ECAP indicated higher shear bond strength. Formation of a layer of intermetallic compounds after annealing treatment is confirmed. In general, by increasing annealing tem...

Autonomously moving micro-objects, or micromotors, have attracted the attention of the scientific community over the past decade, but the incompatibility of phoretic motors with solutions of high ionic strength and the use of toxic fuels have limited their applications in biologically relevant media. In this letter we demonstrate that ultrasonic standing waves in the MHz frequency range can lev...

We report on the correlation between the nanocrystal and surface alloy properties with the bimetallic composition of gold-platinum(AuPt) nanoparticles. The fundamental understanding of whether the AuPt nanocrystal core is alloyed or phasesegregated and how the surface binding properties are correlated with the nanoscale bimetallic properties is important not only for the exploitation of catalyt...

Compared with their monometallic counterparts, bimetallic nanoparticles often show enhanced catalytic activity associated with the bimetallic interface. Direct quantitation of catalytic activity at the bimetallic interface is important for understanding the enhancement mechanism, but challenging experimentally. Here using single-molecule super-resolution catalysis imaging in correlation with el...