Related Experiment Video
Updated: Feb 27, 2026
The Frequency Domain Thermoreflectance Technique for Thermal Property Measurements
Published on: December 5, 2025
Diffraction phase microscopy imaging and multi-physics modeling of the nanoscale thermal expansion of a suspended
Xiaozhen Wang1, Tianjian Lu2, Xin Yu1
1Photonic Systems Laboratory, Department of Electrical and Computer Engineering, Micro and Nanotechnology Lab, University of Illinois at Urbana-Champaign, Urbana, Illinois, 61801, USA.
Abstract:
We studied the nanoscale thermal expansion of a suspended resistor both theoretically and experimentally and obtained consistent results. In the theoretical analysis, we used a three-dimensional coupled electrical-thermal-mechanical simulation and obtained the temperature and displacement field of the suspended resistor under a direct current (DC) input voltage. In the experiment, we recorded a sequence of images of the axial thermal expansion of the central bridge region of the suspended resistor at a rate of 1.8 frames/s by using epi-illumination diffraction phase microscopy (epi-DPM). This method accurately measured nanometer level relative height changes of the resistor in a temporally and spatially resolved manner. Upon application of a 2 V step in voltage, the resistor exhibited a steady-state increase in resistance of 1.14 Ω and in relative height of 3.5 nm, which agreed reasonably well with the predicted values of 1.08 Ω and 4.4 nm, respectively.
