A5091125347- Adhesion, Friction, and Surface Interactions
- Tribology and Lubrication Engineering
- Surface Roughness and Optical Measurements
- Force Microscopy Techniques and Applications
- Characterization and Applications of Magnetic Nanoparticles
- Engineering Technology and Methodologies
- Lubricants and Their Additives
- Gear and Bearing Dynamics Analysis
- Semiconductor Quantum Structures and Devices
- Theoretical and Computational Physics
- Digital Imaging for Blood Diseases
- Phase-change materials and chalcogenides
- Near-Field Optical Microscopy
- Tribology and Wear Analysis
University of California, Berkeley
2023-2025
A typical head–disk interface of hard drives can feature pressures exceeding 50 atmospheres, where the non-ideal gas effects play an important role. One possible consequence is a change in rate water evaporation from disk. This report describes semi-analytical procedure that employs concept fugacity to investigate on saturation pressure at elevated temperature and pressure. vapor–liquid equilibrium equation solved derive The results show deviation ideal law, which further examined through...
A main challenge in Heat-Assisted Magnetic Recording technology is the build-up of contaminants called smear on near field transducer. In this paper, we investigate role optical forces originating from electric gradient formation smear. First, based suitable theoretical approximations, compare force with air drag and thermophoretic head-disk interface for two nanoparticle shapes. Then, evaluate field's sensitivity to relevant parameter space. We find that nanoparticle's refractive index,...
Abstract This report investigates the kinetics of lubricant molecules in HAMR air bearing to understand initiation and growth PFPE contamination on head surface. The collisions with induce three forces—drag, thermophoresis, lift. Of these, we find that lift forces are negligible. Then, a sensitivity analysis remaining two reveals conditions where they dominate. Further, hybrid simulation strategy is utilized track their movements. results show contaminations (smear) highly depend interplay...
This report evaluates the applicability of ideal gas law in pressurized air-bearing hard disk drives when calculating relative humidity. We employ a semi-analytical numerical method that solves vapor-liquid equilibrium using Redlich-Kwong and Peng-Robinson equation state to calculate saturation pressure water. The deviation from is quantified examined through isotherms. find at low temperatures, lighter gases such as helium show little law, whereas heavier nitrogen deviate significantly. As...
Modeling the smear growth in write heads of Heat Assisted Magnetic Recording (HAMR) Disk Drives is an essential tool for understanding mechanisms formation. In this paper, we present a novel method to simulate under influence thermophoretic and drag force. First, time-averaged force field generated using particle mechanics. Then, evaporation condensation parameters, track trajectory random particles on disk. The resulting that form head are plotted compared with experimental results....
Smear is a key issue hindering the reliability of HAMR drives. Under ultra-low spacing, random thermal motions by particles can lead to smear generation on head. To study this phenomenon, we began reducing complexity Head-disk interface (HDI) considering it as three-body problem. Then, using Lennard-Jones potential, calculated interaction energy for particle that eventually forms smear. Finally, Kramer's rate theory, transport from disk