A Simple and Affordable Footwear‐Integrated Near‐Miss Slip Sensor for Detecting Latent Slip Risk During Gait

Slip‐related falls (SRFs) are a leading cause of injury in workplaces and daily life. Wearable inertial sensor systems can detect SRFs, but they do not directly measure available shoe–floor friction. Here, we propose a simple, affordable footwear‐integrated near‐miss slip sensor for investigating latent slip risk during gait. An elastic dome and a two‐stage structure convert changes in the contact stick–slip distribution into normal‐pressure signals. Finite‐element analyses and benchtop tests support this principle. The 15 mm 15 mm 14 mm (3150 mm 3 ) sensor is mounted on the shoe sole at a component cost of approximately US$25 per shoe. During walking, the per‐step pressure ratio distinguished a silicone‐oil–coated floor from the baseline floor ( p < 0.01), with a response time of 120 ms after heel strike. A more durable heel‐embedded variant was used for a secondary gait evaluation in four participants, capturing broader pressure waveforms on the slippery floor across walking speeds. These waveform changes describe gait‐related heel loading rather than direct friction measurement. The proposed sensor provides a compact approach to sensing low‐friction contact conditions associated with latent slip risk, without requiring gross slip. Further design improvements and calibration, combined with independent friction‐demand measurements, could support assessment of the friction margin during walking.