Periodic Reporting for period 4 - Dynamic Nano (Dynamic Nanoplasmonics) Reporting period: 2019-10-01 to 2020-09-30 Summary of the context and overall objectives of the project We used bottom-up (DNA-origami) and top-down (electron beam lithography) nanotechniques to advance the perspective of plasmonics towards synthetic plasmonic machinery as well as on-chip dynamic plasmonic devices with both tailored optical response and active functionality. By creating dynamic plasmonic building blocks with the abovementioned methods, long-standing questions in protein dynamics, chiral sensing, dynamic light matter interaction, gas-phase catalysis, and phase transitions on the nanoscale could be answered. Additionally, routes for ultracompact next-generation optical devices with switchable functionality were explored. Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far We developed plasmonic building blocks for biology, chemistry, and materials science with both tailored optical response and active functionality. The dynamic building blocks allowed us to monitor time dynamics of structural changes, biological processes and phase changes materials down to the single particle level as well as ultrasensitive detection of gases and other substances. Using DNA origami we could not only tailor the plasmonic response but also actively reconfigure and precisely control the structural configuration of nanoplasmonic assemblies even after fabrication. Among other achievements published in many publications, we could for example demonstrate linear motion of nanoparticles or rotation of nanostructures on the nanoscale at nanometer accuracy. These works represent an important step towards artificial plasmonic nanomachines based on DNA origami.The integration of phase change materials into nanoplasmonic assemblies allowed us to endow previously static plasmonic metasurfaces (specially arranged nanoparticles) with dynamic functionalities. We for example used advanced nanofabrication methods to create complex plasmonic building blocks for in-situ sensing of reaction dynamics of gases. Also, the dynamic transformation of nanostructured phase change materials (VO2, conductive polymers and liquid crystals (LCs)) under different external stimuli (hydrogen, temperature or applied electrical fields) was investigated, partially on the single particle level. It turned out that such phase change materials are ideally suited to realize ultrathin optical devices of only a few nanometer thickness with dynamic and even switchable functionality. Following this approach, we could create dynamic colour displays with ultra-high resolution as well as optical devices for dynamic holography, information encryption and beam steering. We further demonstrated multifunctional devices, where the optical functionality could be switched between dynamic holography and dynamic colour display by applying hydrogen. The application potential of such ultrathin optical devices with only nanometer thickness is obvious given the need for display screens and other optical technologies. Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far) DNA origami and nanostructured phase change materials allowed to endow previously static plasmonic building blocks with dynamic and reconfigurable functionalities. It significantly advanced the field of DNA nanophotonics. Artist's illustration of dynamic plasmonic elements enabled by DNA origami
