Nanomechanical thermometry for probing sub-nW thermal transport

Area of Science:

• Physics
• Materials Science
• Nanotechnology

Background:

• Accurate temperature measurement at micro and nanoscales is challenging due to ultra-low thermal transport.
• Optical techniques offer high precision temperature detection, reaching resolutions of approximately 10^-9 K.
• Existing methods often have limitations in resolution, sensing area, or target placement flexibility for nanoscale thermometry.

Purpose of the Study:

• To present a novel nanomechanical device for high-resolution local temperature measurement at the micro and nanoscale.
• To demonstrate nano-Kelvin (10^-9 K) temperature resolution at room temperature and atmospheric pressure.
• To enable precise examination of thermal transport phenomena in micro/nanoscale objects.

Main Methods:

• Development of a nanomechanical device utilizing a 20 nm thick silicon nitride (SiN) membrane forming an air chamber.
• Characterization of the SiN membrane's stiffness and noise equivalent temperature (NET) under pre-stress conditions.
• Measurement of temperature resolution based on the central deflection of the SiN membrane.

Main Results:

• Achieved a nano-Kelvin (10^-9 K) temperature resolution at room temperature and 1 atm.
• The device features a large temperature sensing area (>1 mm²), reducing target placement constraints.
• Demonstrated a heat flow resolution of 100 pW, suitable for micro/nanoscale thermal transport analysis.

Conclusions:

• The presented SiN membrane nanomechanical device offers unprecedented temperature resolution for nanoscale applications.
• The device's large sensing area and high heat flow resolution make it a versatile tool for micro/nanoscale thermal studies.
• This technology advances the capability to investigate thermal transport phenomena at the smallest scales.