  Nanomechanical silicon nitride (SiN) drum resonators are currently employed
in various fields of applications that arise from their unprecedented frequency
response to physical quantities. In the present study, we investigate the
thermal transport in nanomechanical SiN drum resonators by analytical
modelling, computational simulations, and experiments for a better
understanding of the underlying heat transfer mechanism causing the thermal
frequency response. Our analysis indicates that radiative heat loss is a
non-negligible heat transfer mechanism in nanomechanical SiN resonators
limiting their thermal responsivity and response time. This finding is
important for optimal resonator designs for thermal sensing applications as
well as cavity optomechanics.
