The Therma-Lever™ probes used for nano-TA are micromachined silicon probes that are similar in geometry to standard Silicon AFM probes but incorporate a resistive heater at the end of the cantilever. These novel probes have the capability to image the sample surface with lateral resolution close to that of a standard AFM probe, which is significantly better than most thermal probes. Due to the fact that the heater portion of the probe is made of doped silicon, it can be heated repeatedly and reliably to higher temperatures than thermal probes made of thin metal films.
Our Therma-Lever probes come in two models, AN2-200 and AN2-300 which are differentiated in physical geometry. The AN2-200 style is shorter (~200 microns in length) and so is optimized for intermittent contact mode operation. This probe has a typical resonant frequency between 50 and 80 kHz. The AN2-300 is longer with a psring constant less than 1 N/m and so is optimized for contact mode operation. . The local heating of the end of the cantilever is key to the capability of these probes to be used for nano-TA. It means the tip will locally heat the sample surface at the point of contact and that the probe can rapidly both heat and cool. Finally, the local heating eliminates the significant thermal drift associated with bulk heating of the sample as occurs with standard AFM sample heaters.