In-operando infrared absorption method for characterization of composite ceramic membranes during roll-to-roll manufacturing

The Department of Energy’s Water Security Grand Challenge (Goal 1) highlighted a need for new desalination technologies that are cost-competitive with treating freshwater in order to increase low-cost water access and the resilience of the water supply. However, membrane-based desalination processes (i.e., reverse osmosis or electrodialysis) are expensive due to the high cost of membranes. New, cost-effective membranes exist but often fail while scaling to industrially relevant volumes because affordable, accurate, & real-time quality control is not available. The combined Phase I/Phase II projects will deliver a commercially viable inspection system that can detect performance-limiting defects over the whole membrane area during production. The inspection system will leverage infrared thermography technology to observe how applied heat interacts with a membrane to produce real-time feedback on performance-limiting defects. In Phase I, infrared thermography temperature data was successfully correlated to membrane defects such as regions of excess or insufficient coating, pinholes, and cracks. Membrane scanning & testing occurred post-production. For successful correlation, the system’s heat source, sensor, line speed, and image processing were also explored and optimized. To create a minimally viable product, the primary Objectives of Phase II are to (1) install the inspection system on a production line making advanced desalination membranes, (2) create software to acquire image data and identify defects in real-time, and (3) demonstrate broad applicability to advanced membrane materials and changing manufacturing environments. This will require selecting and integrating system components, correlating temperature data with desalination performance, training machine learning algorithms to identify defects, designing a marking and alert system, and finally challenging the system with ultrathin membranes and variable environmental conditions. The rapid feedback provided by this inspection system will enable membrane manufacturers to iterate more quickly and be confident in a consistent product through the quality control aspect of this tool. Beyond membranes for desalination, this technology could be widely adopted for advanced thin film materials made by continuous manufacturing, such as battery separators or flexible, printed batteries and photovoltaics. This taxpayer funded investment will have a multi-faceted impact in the form of job creation, new manufacturing tools, environmental benefits, and federal tax revenue.