Inkjet printing remains a rapidly growing technology, e.g. by replacing offset printing methods, and in various new applications such as printing of diagnostic chips and additive manufacturing. In this project, conducted in collaboration with and supported by a world-leader in inkjet printing technology OCE, based in the Netherlands, we will deepen our insight of the inkjet printing process with unprecedented detail by developing a new state-of-the-art optical technique, high-speed Laser Speckle Imaging, to explore the evolution of an inkjet printed droplet from the moment it is deposited on the substrate of interest. The printing of inks containing dispersed particles, such as binders and pigments, is a complex process that involves a combination of drying, imbibition of solvents into porous substrates, coalescence and film formation. The combination of these phenomena governs not only the dynamics of drying and ultimate consolidation of a printed droplet, but also the quality of the final printed coating. Understanding the dynamics of this process, in particular the internal dynamics of the particle-containing droplets, has remained highly challenging. This is especially the case for printing on porous substrates, where the ratio of evaporative and substrate-driven solvent loss sets the drying and film formation process. The incompleteness of our knowledge of these processes is a major hurdle in establishing robust inkjet printing processes and the development of new sustainable inks free of organic solvents. In this project the PhD candidate will develop a new optical instrument to enable the study of inkjet printing with high spatiotemporal. This will enable us to study in detail the drying, porous wicking, coalescence and film formation within picoliter droplets with micrometer and sub-millisecond resolution. In addition to development, construction and calibration of the optical instrument, the PhD candidate will perform physical measurements to follow inkjet printing in real-time, develop theoretical models to explain these data and collaborate with the industrial partner. We are searching for a candidate with a background in the relevant areas, who works independently and is capable of combining optical instrument development with physical experiments and theoretical studies.

We are looking for a PhD candidate with a strong background in soft matter physics, optics and/or physical chemistry.

We offer you a temporary position for a period of 1.5 years with extension of 2.5 years after successful evaluation. Gross salary per month € 2.222,00 in the first year rising up to € 2.840,00 per month in the fourth year.

We not only offer a competitive salary but also good (study) leave and a pension of the ABP Pension Fund.

Wageningen University & Research

The SprakelLab team is an interdisciplinary research group working at the interface between physics and chemistry, combining experiment, instrument development and theory to understand complex soft materials. Part of the department of Physical Chemistry and Soft Matter at Wageningen University, which works on Soft Matter in the broadest sense of the word. See www.sprakellab.nl and www.pcc.wur.nl

The Agrotechnology & Food Sciences Group is part of Wageningen University & Research, an organisation that brings together fundamental and applied scientific research. We work on creating 'healthy food in a biobased society' with private sector companies, research institutes and government agencies in the Netherlands and abroad. Our innovations play a crucial role in solving the major issues which affect society today. Entrepreneurship and professionalism are key in all that we do. In short, we are a major international employer offering considerable potential for your career.

Wageningen University & Research
Delivering a substantial contribution to the quality of life. That's our focus - each and every day. Within our domain of good and safe food & food production, food security and a healthy living environment, we search for answers to issues affecting society - such as sustainable food production, climate change and alternative energy. Of course, we don't do this alone. Every day, 5000 people work on 'the quality of life', turning ideas into reality, on a global scale.

Could you be one of these people? We give you the space you need.