Sub-picowatt resolution calorimetry with a bi-material microcantilever sensor

We have designed and fabricated bi-material microcantilevers with low conductance by minimizing the width and thickness of the cantilevers while keeping them suitable for detection with an optical deflection technique. The conductance of a cantilever is determined experimentally to be 330 +/- 20nWK(-1). Using this cantilever, we have measured less than 1 pW of heat flow through the cantilever. The thermal noise-limited resolution of the cantilever is expected to be approximate to 50 fW. Such cantilevers give us additional tools to probe thermal transport through nanostructures, especially through single molecules where picowatt-level sensitivity is necessary. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4795625]