Platform for resonant chemical and biosensors based on phononic crystals

• Applicants: Professor Dr.-Ing. Sören Hirsch; Professor Dr. Ralf Lucklum
• Subject Area: Microsystems ; Measurement Systems
• Term: from 2014 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 254691483

The objective of the proposal is the development of a sensor platform for chemical and biosensors satisfying the demand on sensors for microfluidic systems. It combines 5 features:- sensor for liquid phase- sensor for monitoring chemical and biochemical processes in free volume and physiological environment- sample volumes below 1 µl- robust, pure acoustic principle in area of measurement- integration of sensor and micromechanics/microfluidicsThe measurement principle has two unique features not achievable with classical resonant principles:- measurement of the volumetric values speed of sound and sound attenuation of the analyte under inspection- direct relation between measurement values and molecular properties of the analyte and interaction between the constituentsThe development of the sensor platform therefore points to applications in liquid analysis and biophysical studies. The proposed demonstrators are the in-situ measurement of blood glucose in the field of medical technology and the anaylsis of hydrogenolysis of bio-glycerol to 1,2-propanediol in the field of bio diesel production. The sensor principle is based on effects applied in ultrasonic spectroscopy. It takes advantage of resonant features of a defect, simultaneous being the measurement cell of the microfluidic system, introduced to a phononic crystal by purpose. Design and dimensions of the phononic crystal consider the requirements and specifications with respect to sensor sensitivity, typical dimensions of microfluidic systems, and bulk viscosity of the analyte. The transduction scheme of the sensor consists of 2 steps:1. the material specific variation of speed of sound and sound attenuation of the ultrasonic wave traveling through the analyte caused by a specific (bio)chemical reaction, a specific (bio)physical property change of the analyte or a change in concentration of a specific component of the mixture in the measurement cell2. the unspecific shift of the resonance frequency and change in resonance peak amplitude as a result of a change in speed of sound and attenuation of the ultrasonic wave. Design, its optimization and technological realization of the sensor platform are the major tasks of the project, considering high sensitivity and reliability as fundamental requirement for the prospective applications as chemo- or biosensor. The value of the work will be the design of an appropriate phononic crystal including a liquid phase with the required sensing capabilities applying two demonstrators, confirmation and optimization of the volumetric sensor effect, the development of an appropriate micromechanical technology for piezoelectric substrates and the determination of acoustic properties of selected analytes at ultrasonic frequencies and correlation to values of users interest.

• DFG Programme: Research Grants
• International Connection: Canada, Greece
• Participating Institution: SAW Components Dresden GmbH
• Participating Persons: Professorin Dr. Electra Gizeli; Professor Dr. Michael Thompson