A5011622310- Microstructure and mechanical properties
- Metal and Thin Film Mechanics
- Force Microscopy Techniques and Applications
- Aluminum Alloys Composites Properties
- Cellular Mechanics and Interactions
- Metallic Glasses and Amorphous Alloys
- nanoparticles nucleation surface interactions
- Advanced Surface Polishing Techniques
- Copper Interconnects and Reliability
- Microfluidic and Bio-sensing Technologies
- Metallurgy and Material Forming
- Metal Forming Simulation Techniques
- Surface Roughness and Optical Measurements
- Advanced MEMS and NEMS Technologies
- Glass properties and applications
- Advanced Materials Characterization Techniques
- Ion-surface interactions and analysis
- Ultrasonics and Acoustic Wave Propagation
- Mechanical and Optical Resonators
- Micro and Nano Robotics
- Aluminum Alloy Microstructure Properties
- Advanced Electron Microscopy Techniques and Applications
- Surface Treatment and Residual Stress
- Semiconductor materials and interfaces
- Phase-change materials and chalcogenides
Arizona State University
2015-2024
University of Illinois Urbana-Champaign
2006-2011
Indian Institute of Technology Madras
2006
In nanocrystalline metals, lack of intragranular dislocation sources leads to plastic deformation mechanisms that substantially differ from those in coarse-grained metals. However, irrespective grain size, is considered irrecoverable. We show experimentally plastically deformed aluminum and gold films with sizes 65 nanometers 50 nanometers, respectively, recovered a substantial fraction (50 100%) strain after unloading. This recovery was time dependent expedited at higher temperatures....
Forces generated by cells play a vital role in many cellular processes such as cell spreading, motility, differentiation and apoptosis. Understanding the mechanics of single is essential to delineate link between force generation/sensing function. MEMS sensors, because their small size fine force/displacement resolution, are ideal for displacement sensing at single-cell level. In addition, amenability sensors batch fabrication methods allows study large populations simultaneously, leading...
A critical assumption underlying in situ transmission electron microscopy studies is that the beam (e-beam) exposure does not fundamentally alter intrinsic deformation behavior of materials being probed. Here, we show e-beam causes increased dislocation activation and marked stress relaxation aluminum gold films spanning a range thicknesses (80-400 nanometers) grain sizes (50-220 nanometers). Furthermore, induces anomalous sample necking, which unusually depends more on diameter than...
A new compact sensor configuration comprising a single transmitter and multi-receivers (STMR) is presented for the in situ structural health monitoring (SHM) of large plate-like isotropic structures. The STMR exploits long-range propagation characteristics ultrasonic guided Lamb waves phase reconstruction algorithm to provide defect detection location capability under non-dispersive as well dispersive regimes waves. Simulations are performed on defect-free defective finite plates aluminum...
Platelike structures, made of composites, are being increasingly used for fabricating aircraft wings and other substructures. Continuous monitoring the health these structures would aid reliable operation aircrafts. This paper considers use a Lamb wave based structural (SHM) system to identify locate defects in large multilayered composite plates. The SHM comprises single transmitter multiple receivers, coupled one side plate that send receive waves. proposed algorithm processes data...
We present a set of displacement-based high-resolution (50 pN) micromechanical force sensors with large measurement range (1 μN). Typically, that have high resolution limited and vice versa. The presented here overcome this limitation and, in addition, highly linear force-displacement response. (≈3 mm × 4 150 m)are composed series flexible beams attached to rigid probe deform when subjected an external force. is obtained by optically measuring the displacement respect fixed reference beam....
A method to create freestanding, biocompatible polydimethylsiloxane (PDMS) microstructures is presented. First, capillary flow through micro channels on silicon (Si) substrates used high fidelity PDMS structures that are a few μm wide and deep but several mm long (length width/depth ≈ 500:1). Next, an improvised procedure employed remove the cured from Si substrate without damaging them. The extremely sensitive cantilever beams with stiffness less than 0.1 pN/μm, platforms for cell biology...
The flow of liquid polydimethylsiloxane (PDMS, Dow Corning Sylgard 184, 10 : 1 base to cross-linker ratio) in open, rectangular silicon microchannels, with and without a coating (100 nm) poly-tetra-fluoro-ethylene (PTFE), was studied. Photolithographic patterning etching wafers used create microchannels range widths (∼5-50 μm) depths (5-20 μm). Experimental PDMS rates both PTFE-coated uncoated channels were compared an analytical model based on the work Lucas Washburn. experimental matched...
Multi-principal element alloys have the potential to show excellent passivation behavior. However, detailed compositional and crystal structure design of these requires a high-throughput strategy. We used combinatorial thin-film libraries single-phase (FeCoNi)1-x-yCrxAly compared their behaviors corresponding bulk alloys. Our results demonstrate that thin-films are different which is related both nanoscale porosity within grain boundary dissolution. Nevertheless, we found comparisons made...
Abstract Demands for effective high‐temperature electrical conductors continue to increase with the rapid adoption of electric vehicles. However, use conventional copper‐based is limited relatively low temperatures due their poor oxidation resistance and microstructural instability. Here, a highly conductive thermally stable nickel‐graphene‐copper (NiGCu) wire that combines advantages graphene its metallic components developed. The NiGCu consists copper core, an oxidation‐resistant nickel...
The aim of this paper is to evaluate experimentally the switching characteristics discrete high voltage Super-Junction (SJ) MOSFET in 650VDSS class with respect device package. performance SJ evaluated four different SMD packages, which two Kelvin source, each a soft recovery freewheeling diode, its own intrinsic body diode as half bridge configuration and latest generation Silicon Carbide (SiC) Schottky diode. need for overall low inductance hardware design attain better discussed....