Holographic characterization of soft matter opens up new possibilities for the creation of functionalized membrane

In the era of outer space exploration, wearable and smart devices have become more important than ever before. This creates the need for quantitative fabrication of functionalized materials. From liquid film to coating, with the rapid development of manufacturing technology, the demand for real-time characterization of soft materials keeps increasing. Digital holography (DH) has been proven to be a good tool for soft matter measurements; it has been successfully applied in thin film characterization in different scenarios. Here, we demonstrate how a closed-loop manufacturing process based on DH monitoring can help to achieve the fabrication of uniform and ultrathin functionalized polymeric membranes. Thanks to the amazing full-field characterization capability of digital holography at the micrometer scale, detailed information of liquid film evolution is revealed with unprecedented precision. From the motion of liquid flows to nanoparticle clusters on membrane surfaces, holographic imaging demonstrates its inherent ability to perform non-contact, label-free measurements; this allows for continuous iteration of film functionalization process. We believe that holography-based membrane and thin liquid film forming processes will open new possibilities for advanced biomaterials.