Joule heated metallic microwire devices for sub-microsecond T-jump experiments

We report a study of the transient heating response of submicrometric gold wires on oxidized Si substrates, highlighting their potential as versatile platforms for creating fast temperature variations (T-jumps). To characterize electrically the transient heating response, we developed an original differential resistance setup that excites single wires with current pulses and provides a signal proportional to the ΔT induced. A reproducible sub-microsecond transient heating response (for ΔT≤80 °C) was observed for the heaters, regardless the substrate temperature or the presence of a thermal load (polymer film) on the surface. We also developed a simplified mathematical model that reproduced the main experimental observations and provided valuable insights into the dynamics and stability of the heating process. As a proof of concept, our electrical setup was also coupled to a time-resolved optical microscopy setup to detect the transient thermal response of a well-known luminescent thermometer molecule (Rhodamine B).