The Dutch Research Council (NWO) has awarded three million euros to seven early-stage researchers in physics and chemistry through the START-UP programme. Among them, Danqing Liu, assistant professor at the Department of Chemical Engineering and Chemistry of TU/e. Liu receives nearly 411,000 euros, which will be used to develop smart surfaces that can secrete fluids and absorb them from their environment, in response to light or to electric fields. These surfaces will be used to study friction during motion, for self-cleaning systems, and for robotic and health care applications.
Secretion is a common phenomenon in nature. Human skin secretes oil to defend our bodies against bacteria and sweat to regulate our body temperature. Fishes secrete slimy mucus from their skin to protect against parasites and to reduce friction with water to swim faster. Inspired by the skins of living creatures, Danqing Liu develops smart surfaces that can repeatedly release and reabsorb substances under environmental stimuli, such as light and electricity.
Controlled release of liquid from surface area is important for self-cleaning systems, where the released lubricant modifies surface wettability and repels the attachment of various contaminants. Also, it can be used for biomedical purposes, such as skin patches, to control humidity and slowly release antibiotics to cure wounds. And, in a not too far future, smart surfaces could even be used as ‘artificial skins’ of robots.
Making robots sweat
Walking, exercising, raising objects or simply standing still. Every time we use our muscles, they produce heat as a by-product. The more we use them, the more they have to be actively cooled down. This is why we sweat. By sweating, water is pumped out of our bodies, and as that water evaporates, it cools us down.
In robots, especially in humanoid robots placing high torque demands on their motors, the generated heat represents a major constraint on their performance. Currently, engineers solve this problem by using fans or bulky radiators, which take up space and add mass. In the future, the smart surfaces developed by Liu might be used to develop artificial skins which could ‘make robots sweats, cool down and perform better’.
With a broad background in various disciplines, ranging from electrical, to mechanical and chemical engineering, Liu attempts to fill the gap between molecular sciences – such as synthetic organic chemistry – and material science. “I develop new materials like silicones, hydrogels and liquid crystal polymers, at submicrometer length scales”, she explains. These materials are ‘responsive’, meaning that they can sense external stimuli and adapt to those via built-in sensory systems. The latter are either intrinsically present in the materials itself or they can be integrated in the form of optical, electrical or chemical sensors.
Career steps and previous awards
Danqing Liu joined the Department of Mechanical Engineering of TU/e for her PhD research in 2009. In 2013, after receiving her PhD, she joined the Department of Chemical Engineering and Chemistry as a postdoctoral researcher. In 2015 she was appointed Research Fellow at the Institute of Complex Molecular Systems. Since 2019, she is Assistant professor in the group of Stimuli-responsive Functional Materials and Devices led by prof. Albert Schenning, at the Department of Chemical Engineering and Chemistry. Beside the START-UP grant, Liu was awarded a Dutch national 4TU grant (2015), and a VENI grant (2016) from NWO.
End of START-UP programme
The NWO START-UP programme aims at providing a boost to new principal investigators, by giving them the opportunity to refine their creative and high-risk ideas and to establish a basis for future research themes and innovations. With the award of this funding round, the START-UP programme has come to an end. Following a recent letter to parliament (Dutch only) by the Minister of Education, Culture and Science, the sector plan funds allocated through NWO (including the funds for START-UP) will be transferred to direct government funding. This means that after 2020 the Dutch Research Council will no longer have access to this funding and will, therefore, terminate it. Other NWO funding instruments can be found at this link.