Project

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Project We now want to create self-oscillating surfaces . There is a big step to go from reversible response to self oscillating but the stakes is huge. Indeed this would lead to new systems for microfluidic application but also for energy harvesting and why not for biomedical application. If you are willing to take part in this challenging adventure, you will create LCN and characterize them. Later you will activate your system and study their dynamics. Different mixtures and processing conditions will have to be investigated. Surface Dynamics responsive surface topographies Anne Hélène Gélébart and Dick Broer / ST Functional Organic Materials and Devices If you are interested or if you need more information do not hesitate to contact us : Anne Hélène Gélébart ([email protected] , STO 0.39, tel. 040-2478414) Dick Broer ([email protected] , STO 0.27, tel. 040-2475875) Introduction Responsive surfaces have been of interest over the last decade. The creation of micro (and nano) structures on surfaces is very appealing since those protrusions can change the properties of the whole surface : control of the wettability (self-cleaning surfaces), of the friction coefficient (tribology and haptic applications), the optical properties, etc. From previous researches [1] , it has been shown that using a photoresponsive liquid crystal network (LCN) high deformation (up to 10%) can be obtain in an irreversible and especially in a reversible fashion. 1 : D.Liu , 2013, Responsive surface topographies, PhD thesis. Relief formation Figure 1: Isomerization of the azobenzene moieties lead to dimensional changes. Figure 2: Exposure of the LCN under UV light (365nm) under a mask. Figure 3: Example of surface deformation. Under UV exposure the photoresponsive molecule (azobenzene) undergoes isomerization from trans to cis leading in a decrease of molecular order, This is accompanied by dimensional changes as shown on the Figure 1. When a LCN is exposed to the UV light the same mechanism will occurs leading to the formation of protrusion at the exposed areas (Figure 2). The shape of the deformation can be tuned using different masks. The measurement of the deformation is done using a interferometer, figure 3 shows an example of deformation that can be obtained.

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Surface Dynamics responsive surface topographies Anne Hélène Gélébart and Dick Broer. Introduction - PowerPoint PPT Presentation

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ProjectWe now want to create self-oscillating surfaces. There is a big step to go from reversible response to self oscillating but the stakes is huge. Indeed this would lead to new systems for microfluidic application but also for energy harvesting and why not for biomedical application. If you are willing to take part in this challenging adventure, you will create LCN and characterize them. Later you will activate your system and study their dynamics. Different mixtures and processing conditions will have to be investigated.

Surface Dynamicsresponsive surface topographies

Anne Hélène Gélébart and Dick Broer

/ ST Functional Organic Materials and Devices

If you are interested or if you need more information do not hesitate to contact us : Anne Hélène Gélébart ([email protected], STO 0.39, tel. 040-2478414)Dick Broer ([email protected], STO 0.27, tel. 040-2475875)

IntroductionResponsive surfaces have been of interest over the last decade. The creation of micro (and nano) structures on surfaces is very appealing since those protrusions can change the properties of the whole surface : control of the wettability (self-cleaning surfaces), of the friction coefficient (tribology and haptic applications), the optical properties, etc. From previous researches[1], it has been shown that using a photoresponsive liquid crystal network (LCN) high deformation (up to 10%) can be obtain in an irreversible and especially in a reversible fashion.

1 : D.Liu , 2013, Responsive surface topographies, PhD thesis.

Relief formation

Figure 1: Isomerization of the azobenzene moieties lead to dimensional changes.

Figure 2: Exposure of the LCN under UV light (365nm) under a mask.

Figure 3: Example of surface deformation.

Under UV exposure the photoresponsive molecule (azobenzene) undergoes isomerization from trans to cis leading in a decrease of molecular order, This is accompanied by dimensional changes as shown on the Figure 1. When a LCN is exposed to the UV light the same mechanism will occurs leading to the formation of protrusion at the exposed areas (Figure 2). The shape of the deformation can be tuned using different masks. The measurement of the deformation is done using a interferometer, figure 3 shows an example of deformation that can be obtained.