Sensor devices based on integrated, functionalized carbon nanotubes

• Applicant: Professor Dr.-Ing. Stefan E. Schulz
• Subject Area: Microsystems
• Term: from 2011 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 195215523

The outline for phase 2 of TP5 contains four work packages as follows: AP1 "Sensor platform and piezoresistive sensor", AP2 "Optical sensor", AP3 "Concepts for synthesis and CNT functionalization" und AP4 "Monolithic integration of CNT-based sensor devices".AP1 is continuously dedicated to the integration of CNTs in microelectromechanical systems (MEMS). Especially the formation of an electrical contact between the CNT and metal electrodes and its reliabililty during operation appeared to be challenging. In order to answer related questions, we plan more comprehensive investigations using the nanomanipulator launched in phase 1 and electron microscopy, in close co-operation with TP3. The existing test platform will be further developed to optically and/or electronically characterize single CNTs in operation under mechanical load. In co-operation with TP2 and TP3, we plan the design and manufacturing of MEMS structures with thermal actuators for the characterization of CNT-based, piezoresistive sensors.AP2 and AP3 have the aim to apply the on-chip functionalization of integrated CNTs with metal nanoparticles succesfully shown in phase 1 to achieve optical sensors via microtechnological processing. For this aim, AP 3 will evaluate the necessary approaches for a chemical functionalization, with the most auspicious ones to be conjoined with the wafer-level technology in AP 2. On its part, AP 2 will develop a suitable device geometry and derive and execute a possible microtechnological process plan. The particular task is in that, to improve the transformation of the successful lab-scale juxtaposition of metal nanoparticles on CNTs to the microtechnological environment with respect to controlling the selectivity, degree and density of functionalization. As a central, new approach we plan to employ elongated gold and silver nanoparticles alongside with spherical ones. For the former, a novel synthesis route could be reported already during the first phase. The characterization of the nanostructures will be carried out along two pathes: first, the determination of the structural properties of the involved nanoscale constitutents, second, the characterization of the functional properties of the entire system (current-voltage characteristics, absorption, efficiency, polarization).Finally, AP 4 will develop a strategy for a monolithically integrated CNT-based sensor system in close co-operation with TP7. In the beginning, it is based on the parameters expected for the optical CNT-based sensors. In the course of the project, the input for this task shall increasingly be derived from the experimental measurements in AP 3.

• DFG Programme: Research Units
• Subproject of: FOR 1713: Sensoric Micro- and Nanosystems
• Participating Persons: Professor Dr. Heinrich Lang; Professor Dr. Thomas Otto