Air quality and the associated subjective and health-related quality of life are among the important topics of urban life in our time. However, it is very difficult for many cities to take measures to accommodate today’s needs concerning e.g. mobility, housing and work, because a consistent fine-granular data and information on causal chains is largely missing. This has the potential to change, as today, both large-scale basic data as well as new promising measuring approaches are becoming available.
The project “SmartAQnet”, funded by the German Federal Ministry of Transport and Digital Infrastructure (BMVI), is based on a pragmatic, data driven approach, which for the first time combines existing data sets with a networked mobile measurement strategy in the urban space. By connecting open data, such as weather data or development plans, remote sensing of influencing factors, and new mobile measurement approaches, such as participatory sensing with low-cost sensor technology, “scientific scouts” (autonomous, mobile smart dust measurement device that is auto-calibrated to a high-quality reference instrument within an intelligent monitoring network) and demand-oriented measurements by light-weight UAVs, a novel measuring and analysis concept is created within the model region of Augsburg, Germany. In addition to novel analytics, a prototypical technology stack is planned which, through modern analytics methods and Big Data and IoT technologies, enables application in a scalable way.
In this work we report on the development of electrostatically actuated RF MEMS switches which are based on a one
sided clamped cantilever made of two layers of the same alloy of aluminum-silicon-copper. The switches are based on a
low-complexity design and are fabricated by conventional sputter deposition and wet etching techniques on oxidized
silicon substrates. Due to a well defined intrinsic stress gradient the cantilevers bend away from the substrate surface
after release. This deflection allows the combination of high open-state isolation with a moderate pull-in voltage and
with high restoring forces, which help to reduce sticking effects. The temperature behavior of the residual stress of each
single layer that are the basis for the switch is investigated up to 400°C. Thereby, the change in stress over temperature
as well as stress level in the as-deposited state is strongly dependent on deposition parameters. Furthermore, the change
of deflection is evaluated up to 400°C at cantilever-type test structures. Finally, the high frequency performance of the
switches was measured in the 23 to 36 GHz range showing good results for isolation and insertion loss.