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Elastic properties modulation on 2D WS2 membranes NEMS

Overview

Our group investigates how nanoscale structural design can be used to tailor the mechanical and elastic properties of two-dimensional (2D) materials. In particular, we have demonstrated that the strain, stiffness, and tension of suspended 2D (e.g., WS2, MoS2) membranes can be actively modulated through strain engineering via structural and gate-voltage tuning. By precisely measuring the resonant vibrational modes of these ultrathin membranes, we quantitatively extract their elastic constants and intrinsic tension, revealing how nanoscale patterning influences mechanical stiffness and strain distribution.  

Featured Publications:

Multimode tunable atomically thin vibrating-channel-transistor resonators with ultra-efficient electromechanical transduction 

We leverage the atomic-scale thickness, ultrahigh strain limit, as well as strain-engineering effects on band structure and carrier mobility of 2D molybdenum disulfide (MoS2) sheets, and experimentally demonstrate multimode 2D MoS2 VCT resonators. These 2D VCT resonators provide a unique platform for engineering on-chip integrated and ultra-scaled RF signal transduction, sensing, and analog computing elements with multimode and hyperspectral capabilities. 

Thermal Response and TCf of GaN/AlN Heterostructure Multimode Micro String Resonators From −10 °C Up to 325 °C

Comparison among different devices indicates that higher tensile stress levels contribute to smaller TCf values, suggesting strain engineering may be exploited for intentionally regulating the TCf. The investigation of TCf may provide helpful insight into analyzing how fluctuations in temperature can affect the characteristics and performance of GaN/AlN resonators with residual (built-in) tensile stress.

References:

  • [Featured Article & Editor’s Pick] Yang R, Lee J, Feng PXL*, “Multimode Tunable Atomically Thin Vibrating-Channel-Transistor Resonators with Ultra-Efficient Electromechanical Transduction”, Applied Physics Reviews 12, 031416 (2025).  DOI: https://doi.org/10.1063/5.0238991
  • Sui W, Zheng XQ, Lin J-T, Alphenaar BW, Feng PXL*, “Thermal Response and TCf of GaN/AlN Heterostructure Multimode Micro String Resonators from -10°C up to 325°C”, Journal of Microelectromechanical Systems 30, 521-529 (2021).  DOI: https://doi.org/10.1109/JMEMS.2021.3089703.  [Featured as 1 of the 3 “JMEMS RightNow Papers” in the August 2021 Issue]