# Analysis of the effect of pressure force on the microstructure properties of pressure measuring films

## TL;DR

This paper studies how pressure affects the microstructure of pressure measuring films, aiming to improve understanding and accuracy of these tools.

## Contribution

The study provides a detailed analysis of microstructural changes and chemical composition in pressure measuring films under force loading.

## Key findings

- Microstructural properties of transfer sheets change with applied force.
- Chemical composition analysis revealed non-uniform distribution of microcapsules.
- Measurement accuracy of ±15% is linked to pre-damaged microcapsules.

## Abstract

Pressure measuring films make it possible to determine pressure in the contact zone. The solution is now successfully used in various scientific and industrial sectors, e.g., for research in medicine (orthopaedic template design), mechanical engineering or geology. Among the available types of pressure measuring system, mono-sheet or two-sheet films type can be found. This article focuses on the study of transfer sheets included in the set of two-sheet type films, within the framework of the described research work, qualitative and quantitative analyses of the transfer sheet microstructure were carried out with the aim of determining the changes in the microstructural properties of this sheet that occur as a result of force loading. There is a lack of description of the phenomena occurring during the use of pressure measurement films in the available literature. All research done to date was focused on practical use of this method in measurement of contact area or pressure distribution. The presented experimental results, together with a detailed description, will allow the reader to better understand the principle of operation and the mechanisms of phenomena that occur during pressure measurements using pressure measuring films. In addition, an analysis of the chemical composition of both sheets was carried out. The knowledge of the distribution of the microcapsules (size and number of pre-damaged ones) can be used in numerical simulation with the pressure measurement films. Also the manufacturers range of measurement accuracy (± 15%) was clarified by measuring the number of the pre-damaged microcapsules and non-uniform distribution of microcapsules.