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Full-Text Articles in Engineering
Highly Effective Geni Alloy Contact Diffusion Barrier For Bisbte Long-Term Thermal Exposure, Erdong Song, Brian S. Swartzentruber, Chowdary R. Koripella, Julio A. Martinez
Highly Effective Geni Alloy Contact Diffusion Barrier For Bisbte Long-Term Thermal Exposure, Erdong Song, Brian S. Swartzentruber, Chowdary R. Koripella, Julio A. Martinez
Publications and Research
A GeNi alloy diffusion barrier for contacts on bismuth antimony telluride is proposed. Multiple gold contact diffusion barriers were tested at different thermal aging conditions in air and reducing atmospheres. Among all diffusion barriers, the GeNi alloy barrier shows the best performance for bulk samples with no substantial degradation of the contact resistance, no contact color change, and no change of thermoelectric properties. We observed DAu−GeNi = (9.8 ± 2.7) × 10−20 m2/s within the GeNi alloy barrier, which is 4 times smaller than DAu−BiSbTe. The presence of the initial Ge layer also proves to be effective in reducing nickel …
The Modeling, Design, Fabrication, And Application Of Biosensor Based On Electric Cell-Substrate Impedance Sensing (Ecis) Technique In Environmental Monitoring, Xudong Zhang, William Wang, Sunghoon Jang
The Modeling, Design, Fabrication, And Application Of Biosensor Based On Electric Cell-Substrate Impedance Sensing (Ecis) Technique In Environmental Monitoring, Xudong Zhang, William Wang, Sunghoon Jang
Publications and Research
In this research, the modeling, design, fabrication, and application of ECIS sensors in environmental monitoringare studied. The ECIS sensors are able to qualify the water toxicity through measuring the cell impedance. A novel mathematical model is proposed to analyze the distribution of electric potential and current of ECIS. This mathematical model is validated by experimental data and can be used to optimize the dimension of ECIS electrodes in order to satisfy environmental monitors. The detection sensitivity of ECIS sensors is analyzed by the mathematical model and experimental data. The simulated and experimental results show that ECIS sensors with smaller radius …
Å-Indentation For Non-Destructive Elastic Moduli Measurements Of Supported Ultra-Hard Ultra-Thin Films And Nanostructures, Filippo Cellini, Yang Gao, Elisa Riedo
Å-Indentation For Non-Destructive Elastic Moduli Measurements Of Supported Ultra-Hard Ultra-Thin Films And Nanostructures, Filippo Cellini, Yang Gao, Elisa Riedo
Publications and Research
During conventional nanoindentation measurements, the indentation depths are usually larger than 1–10 nm, which hinders the ability to study ultra-thin films (<10 >nm) and supported atomically thin two-dimensional (2D) materials. Here, we discuss the development of modulated Å-indentation to achieve sub-Å indentations depths during force-indentation measurements while also imaging materials with nanoscale resolution. Modulated nanoindentation (MoNI) was originally invented to measure the radial elasticity of multi-walled nanotubes. w, by using extremely small amplitude oscillations (<<1 Å) at high frequency, and stiff cantilevers, we show how modulated nano/Å-indentation (MoNI/ÅI) enables non-destructive measurements of the contact stiffness and indentation modulus of ultra-thin ultra-stiff films, including CVD diamond films (~1000 GPa stiffness), as well as the transverse modulus of 2D materials. Our analysis demonstrates that in presence of a standard laboratory noise floor, the signal to noise ratio of MoNI/ÅI implemented with a commercial atomic force microscope (AFM) is such that a dynamic range of 80 dB –– achievable with commercial Lock-in amplifiers –– is sufficient to observe superior indentation curves, having indentation depths as small as 0.3 Å, resolution in indentation <0.05 Å, and in normal load <0.5 nN. Being implemented on a standard AFM, this method has the potential for a broad applicability.