A Method for Measuring Fluid Pressures in the Shoe-Floor-Fluid Interface: Application to Shoe Tread Evaluation

Area of Science:

• Tribology
• Biomechanics
• Materials Science

Background:

• Fluid contaminants on surfaces reduce shoe-floor friction, leading to slipping accidents.
• Understanding fluid pressures at the shoe-floor interface is crucial for preventing slips, but measurement technology has been lacking.
• This gap has hindered research into factors influencing fluid pressures and slip risk.

Purpose of the Study:

• To introduce a novel technique for measuring fluid pressures beneath footwear.
• To demonstrate the technique's utility by quantifying the impact of tread depth and fluid viscosity on measured pressures.
• To analyze these effects for athletic and work shoe designs.

Main Methods:

• A fluid pressure sensor was integrated into the floor surface.
• A robotic slip-tester was used to move shoes across the sensor-equipped surface.
• 2D fluid pressure maps were generated by collecting multiple scans under varying conditions (shoe type, fluid viscosity, tread depth).

Main Results:

• High fluid pressures were recorded for untreaded shoes with high-viscosity fluids.
• Treaded shoes and low-viscosity fluids resulted in significantly lower fluid pressures.
• Observed pressures for untreaded shoes align with tribological theory and human slip data.

Conclusions:

• The developed method accurately measures fluid pressures under shoes.
• Results validate tribological principles and findings from human slip experiments.
• This technique can assess footwear slip resistance and establish optimal shoe replacement intervals based on wear.