Multi-Station Pin-on-Disk Orthopaedic Tribometer
Applies controlled reciprocating motion and normal load with continuous cycle counting.
Biomedical Engineering / UHMWPE Joint Wear Factor
FREE TO EXPLORELABORATORY 21 · BIOMEDICAL ENGINEERING
UHMWPE Artificial Joint Bearing Pin-on-Disk Wear Factor Testing
Determine the Archard volumetric wear factor k_w of medical-grade ultra-high-molecular-weight polyethylene (UHMWPE) sliding against CoCr alloy in bovine serum. Explore interactive physiological instrumentation simulation, biomechanics, and biomedical engineering telemetry.
BIOINSTRUMENTATION · BIOSIGNALS · BIOMECHANICS · IMAGING
Your virtual biomedical engineering laboratory.
VOLUMETRIC WEAR LOSS V_W—
PHYSIOLOGICAL & TEST CELL TELEMETRY
Ready to sample with Distance L_s = 6.0 km.
Adjust Distance L_s, then execute biomedical trial.
Biomedical engineering telemetry and physiological states are evaluated rigorously using 64-bit IEEE 754 precision. Residuals reflect ordinary least-squares regression across successive observations. Continuous data structures support high-fidelity biological and physiological modeling.
Biomedical assumptions and boundary condition limits
The simple pin-on-disk geometry does not replicate multi-directional cross-shear kinematics found in clinical hip gait cycles. Evaluated on medical GUR 1020 UHMWPE cylindrical pins (diameter 9.5 mm, contact area 71 mm²) articulating against mirror-polished CoCrMo disks (Ra = 0.015 μm) in 25% bovine serum at 37 °C. Constant normal load F_N = 200 N at 1.0 Hz cyclic articulation. Linear wear rate k_w = 2.1500 mm³/km.
Biomedical apparatus & physiological sensors.
Medical Grade GUR 1020 UHMWPE Test Pins
Standardized cylindrical polymer bearing specimens machined from compression-molded rod.
Mirror-Polished CoCrMo Articulation Disks (Ra < 0.02 μm)
Represents metallic femoral prosthetic counterface meeting ISO 5834 surface standards.
Thermostatically Controlled Serum Bath (37.0 °C)
Maintains 25% bovine calf serum lubricant with 0.2% sodium azide antibacterial agent.
Sub-Microgram Ultra-Microbalance (0.1 μg resolution)
Measures gravimetric wear loss before and after sliding intervals with vacuum desiccator drying.
Soak-Control Unloaded UHMWPE Reference Pin
Corrects for fluid absorption mass gain to isolate true tribological wear mass loss.
FOLLOW THE METHOD
A reason behind every step.
Determine the Archard volumetric wear factor k_w of medical-grade ultra-high-molecular-weight polyethylene (UHMWPE) sliding against CoCr alloy in bovine serum. Standardized parameter settings: 2.0, 4.0, 6.0, 8.0, 10.0, 12.0 km.
01
Specimen Cleaning and Initial Mass Metrology
Clean UHMWPE test pins and unloaded soak-control pins in ultrasonic baths of ethanol and deionized water, vacuum desiccate for 48 hours, and weigh on ultra-microbalance (m_0).
02
Disk Counterface Profilometry
Measure mirror-polished CoCrMo disk surface roughness using optical profilometry, verifying Ra < 0.02 μm across the circular wear track.
03
Lubricant Preparation and Chamber Thermal Equilibration
Fill tribometer reservoir with 25% bovine calf serum containing 0.2% sodium azide, heat to 37.0 °C, and verify temperature stability.
04
Normal Load Application and Kinematic Run
Mount the UHMWPE pin in the articulated holder, apply 200 N normal force via deadweights, and initiate reciprocating circular motion at 1.0 Hz.
05
Periodic Gravimetric Interruption and Soak Correction
At sliding intervals of 2, 4, 6, 8, 10, and 12 km, remove pins, clean, desiccate, reweigh, and correct for soak fluid absorption: Δm = (m_0 - m_t) + Δm_soak.
06
Volumetric Wear Rate Calculation
Convert corrected mass loss to volume loss V_w = Δm / ρ (UHMWPE density ρ = 0.935 g/cm³), plot V_w versus sliding distance L_s, and calculate wear rate k_w.
YOUR NOTEBOOK · 0 OBSERVATIONS
Turn measurements into biomedical engineering insight.
Points are your recorded observations. The solid regression line validates UHMWPE Joint Wear Factor mathematical scaling.
LINEAR REGRESSION FIT · y = mx + b
V_w = k_w · L_s = 2.1500 · L_s (under constant 200 N normal load)
| # | Total Sliding Distance L_s (km) | Volumetric Wear Loss V_w (mm³) | Sliding distance L_s (km) | Volumetric wear loss V_w (mm³) | Remove |
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