X-Ray Diagnostics

High-Efficacy X-Ray Diagnostic Tools for Process Optimization and Quality Management on Roll-to-Roll and Conveyor-based Manufacturing Lines

Batteries, fuel cells, solar cells, flexible electronics as well as thermal and environmental coatings in building products like smart windows all rely on roll-to-roll or conveyor-based manufacturing solutions. These high performance and functional coatings often have layers with complex structures and compositions. Incorporating a third-dimension into an inherently two-dimensional sheet through structure and compositional gradients while increasing processing speeds requires new diagnostic tools for process development, optimization, and in-line quality management.

There currently exist a number of diagnostic tools for in-line measurement of thickness, detection of cracks and defects, and material composition. While these enable measurement of coating thickness, identification of some defects in processing, or measuring the chemical composition, they do not provide information about internal structure through the depth of the sheet. In this project, we propose to leverage the rapid improvement in x-ray detectors to develop and deliver sensing diagnostics for high-throughput sheet-based manufacturing providing detailed information about the structure and composition of the coated layers.

Structure of the X-Ray Diagnostics project with two key measuring technologies

Scope of Research Activities
Material and Coating Development

Preparation of solar cell thin films with characteristic textures and manufacturing defects
Preparation of wet-coated particles systems
Preparation of dry battery electrodes and solid-state battery electrodes

X-Ray Grating Interferometry (GI) Imaging

Testing of materials and development of analysis code
Design and construction of prototype
Refinement of prototype system

X-Ray Diffraction (XRD) Texture Measurements

Testing of materials and development of analysis code
Design and construction of prototype
Refinement of prototype system

Diagnostics on Belt and Roll-to-Roll (R2R) Systems

Design and construction of prototype conveyor system
Trials at coating lines
Evaluation of x-ray diagnostics tool for R2R as product concept

Key Challenges and Technical Problems to Solve

Develop tools that provide information about internal structure and composition through the depth of the sheet
Process obtained information rapidly that it can be interpreted by a machine, generate a feedback criterion, and be used to automate and add intelligence to manufacturing
Integrate the new x-ray diagnostic tools into commercial coating lines

Demonstrator

Portable x-ray GI imaging prototype for integration into a commercial coating line
Portable XRD texture measurement prototype for integration into a commercial coating line
Demonstrator of x-ray diagnostic tools capable of quantifying and monitoring structural feature on a commercial coating line

Leading Principal Investigator

Prof. Dr. Vanessa Wood
Laboratory for Nanoelectronics, ETH Zürich

Project Consortium

Prof. Dr. Ayodhya Tiwari
Laboratory for Thin Films and Photovoltaic (LTFPV), Empa
Prof. Dr. Marco Stampanoni
X-Ray Tomography Group (TOMCAT), PSI