Cantilever-based sensor platforms

This system can be easily scaled up allowing the detection of different concentrations and/or different analytes simultaneously. For biological experiments, arrays of cantilevers are normally employed (5) as one cantilever can be used as reference. Then the expected biointeraction can be diferenciated from any change of the experimental conditions. Actually, there are several commercial platforms available, based on cantilever-array sensors. 

Recently Micro Electro-Mechanical Systems (MEMS) have been emerging as sensor platform for the development of sensors with extreme high sensitivity [8-14]. Micromachined silicon cantilevers are the simplest MEMS sensors that can be micromachined and mass-produced. Microcantilever sensor technology is an upcoming sensing technique with broad applications in chemical, physical, and biological detection. With their compactness and potential low cost, detection techniques based on silicon-based cantilevers provide a path for the development of miniaturized sensors. 

In the best-case situation, both types of microcantilever sensors would be grouped in an array to provide a cross platform of sensitive and selective explosive detection system. Additional co-funded (TSA/ATF) work is eurrently on going in materials development for novel microeantilevers. This involves R D of silicon carbide (SiC) based cantilevers, for improvements in material properties (e.g., less fragile eompared to silicon) and to provide a platform for wide band gap type materials, like aluminum nitride (AIN). With an AlN/SiC based cantilever, the sensor can now work in the piezoeleetric resonator mode, providing enhance response and henee sensitivity to the analyte, along with a direct measurement by frequeney/resistance response, versus the more complex optieal deteetion... 

We have demonstrated an extremely sensitive sensor platform for groundwater monitoring. The sensitivity of the cantilever sensor depends on cantilever dimension, while the selectivity depends on die selectivity of the surface coating for chemical interactions. Research is underway to develop cantilever arrays for simultaneous multi-analyte detection. The primary advantages of the microcantilever method are (1) the sensitivity of microcantilevers based on their ability to detect cantilever motion with subnanometer precision (2) their ability to be fiibricated into multi-element sensor arrays and (3) their ability to work in a liquid environment. 

Lang HP, FUippi A, Tonin A, Huber F, Backmann N, Zhang J, Gerbe C (2009) Towards a modular, versatile and portable sensor system for measurements in gaseous environments based on microcantilevers. Procedia Chem 1 208-211 Lavrik NV, Sepaniak MJ, Datskosa PG (2004) Cantilever transducers as a platform for chemical and biological sensors. Rev Sci Instrum 75(7) 2229-2253... 

---