Meaning
Force-sensitive sensor sheet displays the distribution and magnitude of localized mechanical forces between contacting surfaces through color density changes. Tactile pressure film measures the uniformity of stack pressure within battery test fixtures and assembled solid-state cell stacks. It provides a visual and quantitative record of the pressure gradients that exist across the active area of the cell.
By identifying high-pressure zones, manufacturers can adjust the tightening torque of the fixture bolts to avoid localized mechanical stress on the cells.
Measurement Principle
Micro-encapsulated color-forming material on the film ruptures under applied pressure, releasing a developer that produces a red color. The intensity of the red color is directly proportional to the magnitude of the applied mechanical stress. Digital analysis of the film provides high-resolution pressure maps of the interface.
Battery Application
Non-uniform pressure can cause uneven electrode utilization, leading to localized lithium plating and accelerated cell degradation. Engineers use the film to align compression plates and evaluate the compliance of elastomeric spacer pads. This alignment is critical for optimizing the cycle life of pouch cells.
Selection Criterion
Sourcing the correct film grade depends on the expected operating pressure range of the battery stack. Low-pressure grades are suitable for assessing soft pouch cells, while high-pressure grades are used for rigid solid-state test cells. Correct grade selection ensures accurate pressure measurements.
