Surface acoustic wave (SAW) biosensors offer label-free, rapid, sensitive, and cost-effective detection of analytes in liquid samples. Applications include the detection of disease markers in blood or contaminants in food or environmental samples. Common SAW devices for sensing applications include delay line devices and resonators, the latter allowing for simple and low-cost collection of the resonance frequencies by oscillators. The velocity of the SAW, and thus the resonance frequency, is mainly influenced by mass changes on the device surface due to analyte binding, which is typically the desired parameter, but also by viscosity and conductivity changes in the liquid environment. In particular, the response to conductivity changes can interfere with the mass loading response and would therefore be desirable to eliminate. It has been shown previously that conductive layers can be used to eliminate this unwanted effect, but the setup required extensive machinery. The focus of this work is to apply metal coatings to SAW resonators using simple methods and then to test the metal-coated resonators in biosensor experiments.

Your tasks include:

• Selection of metal (type and form) to be used as the conductive coating
• Developing a protocol to apply the metal to the SAW resonators without the use of extensive machinery
• Testing of the stability of the metal coatings
• Characterization of the metal-coated SAW resonators
• Testing of the performance of the metal-coated SAW resonators in a biosensor measurement

The number and depth of the tasks will be adapted to the type and length of the work, i.e., bachelor or master thesis. The thesis can be written in German or English.

• Study of a relevant subject, such as mechanical engineering, chemical engineering, bioengineering, mechatronics, physics, chemistry, analytical chemistry, biotechnology
• Practical skills, having worked in a (chemistry) laboratory, e.g. on a laboratory course
• Willingness to work in a multidisciplinary environment