Individual shape adaptation of microlenses by means of electric fields

• Applicant: Professor Dr. Andreas Heinrich
• Subject Area: Microsystems
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 440697245

Microlenses show a wide application in optics. Thereby it would be especially of advantage to allow an individualized form of such microlenses. In general, 3D printing enables a high level of individualization of components.The aim of this project is to investigate whether it is possible to deform a 3D printed liquid polymer (=microlens) with the help of electric fields and then cure it. This allows a new way to realize microlenses with free-form surfaces. A basic understanding, e.g. with regard to the relationship between the distribution of the electric fields and the lens shape, as well as with respect to the material properties of the polymers and the resulting forms are worked out in this project. It is also necessary to investigate how the optical properties relate to the realizable shape and the material properties. The general aim of this project is to examine the topic from different perspectives, i.e. to consider the interplay of optical properties, 3D printing, electrical fields and material properties experimentally and via simulation models in order to gain a holistic, deeper understanding. In detail, the following goals should be achieved:The influence of different electric field distributions (at different intensities) on the deformation of the printed liquid polymer droplets (for different materials, substrates and print volumes) has to be investigated. Here, material parameters such as polarizability, viscosity, shrinkage during curing or topics such as the interaction between substrate and droplets play an important role. In order to grasp these relationships and to gain a deeper understanding, it is necessary to build up corresponding simulation models in Matlab and ANSYS and to validate them on the basis of experiments. In doing so, it is crucial to correlate the material aspects with the deformations achieved by the electric fields, which ultimately determines the optical performance of the microlens.The above-mentioned examinations should then be expanded. On the one hand, a pre-structuring of the substrates needs to be carried out in order to enable further boundary conditions for the formation of droplets and deformation. On the other hand, a defined symmetrical surface structure should be generated, e.g. by standing surface waves, as this would be desirable for many optical applications. Once again, it is important to combine the interplay of optics, electrical fields and material aspects with each other and to consider them holistically.Finally, a micro lens system based on several lenses should be realized and studied in detail. In addition to the question of the optical performance of the system, questions wrt. material science (diffusion, cracks, etc.) need to be addressed as well, e.g. at the boundary layer between two microlens elements.

• DFG Programme: Research Grants