Absorption microscopy is a powerful technique, enabling the detection of single non-fluorescent molecules at room temperature. We show that nanomechanical photothermal sensing surpasses the shot-noise-limited sensitivity of state-of-the-art optical absorption techniques by more than two orders of magnitude.
Using stress-optimized silicon nitride resonators, we achieve femtowatt-sensitivities at room temperature. Such a sensitivity not only results in unprecedented signal-to-noise ratios for the imaging of single molecules, but it is on a par with the sensitivity of liquid helium cooled IR/THz photodetectors. Room temperature nanomechanical photothermal sensors hence present a competitive alternative to i) established imaging tools, such as electron or optical microscopy, and ii) cooled broadband IR/THz photodetectors.
Silvan Schmid completed his mechanical engineering education from ETH Zurich in 2003. He performed his doctorate in the Micro and Nanosystems Group at ETH Zurich and received his doctoral degree in 2009. After his doctorate, Silvan Schmid started a postdoc position at the Technical University of Denmark (DTU). In 2012 he received the Villum Foundation's Young Investigator Programme grant, which allowed him to independently conduct his own research as an Assistant Professor and later as Associate Professor at DTU. In 2016 Silvan Schmid got appointed Full Professor at TU Wien, where he since heads the Micro and Nanosensors Group at the Institute of Sensor and Actuator Systems. Also in 2016, he received an ERC Starting grant to work on nanoplasmomechanical systems.