Converse flexoelectric actuators offer significant potential for diverse applications due to their rapid response, resilience in extreme environments, and broad material compatibility. However, their development has been limited, primarily because flexoelectric effects are negligible in bulk materials. At the nanoscale, the converse flexoelectric effect becomes much more promising, as the electric field gradient scales quadratically with decreasing material thickness. Here, we report a converse flexoelectric actuator based on two-dimensional molybdenum disulfide. Under alternating current excitation near 20 kHz, the actuator exhibits resonant displacements up to ~45 nm, approximately two orders of magnitude larger than the thickness of the molybdenum disulfide active layer. This performance exceeds that of existing flexoelectric actuators by more than an order of magnitude when normalized by active layer thickness. Moreover, the actuator maintains strong flexoelectric responses under extreme conditions, including vacuum, cryogenic temperatures, and repeated cycling, highlighting the robustness and broad applicability of two-dimensional material-based converse flexoelectric systems.

[Access this dataset on Dryad: https://doi.org/10.5061/dryad.xksn02vwc]

These files contain the data associated with the article “Converse Flexoelectric Two-dimensional MoS₂ Actuator,” which has been published in Nature Communications, https://doi.org/10.1038/s41467-026-69271-w. We have submitted our raw and calculated data, including displacement measurements of the fabricated actuators obtained using a laser vibrometer, as well as electric field, electric field gradient, resonant frequencies, and harmonic displacements calculated using COMSOL Multiphysics software.

Description of the data and file structure

Each folder and file name indicates the corresponding figure number. All files were generated using Microsoft Excel and saved as .csv files, which is the standard file format for Dryad. The unit for each variable is indicated in parentheses. Below is a description of each file.

Figure 2 folder

Figure2a.csv: Maximum displacement of a monolayer device at different excitation frequencies.

AC Frequency (Hz): Frequency of the AC excitation applied to the device.
Fast Fourier transformed vibrometer signal (dB): The maximum magnitude of the laser doppler vibrometer output signal after fast Fourier transform (FFT) performed by the oscilloscope.
Velocity (m/s): The device velocity calculated from the fast Fourier transformed vibrometer signal.
Displacement (nm): The device displacement calculated from the velocity.

Figure2b_and_S3.csv: Applied electric-field vs displacement of different devices.

Resonance Frequency (Hz): Frequency of the AC excitation applied to the device at which the maximum displacement occurred.
Vpp (V): Peak-to-peak amplitude of the applied AC voltage.
E-field (kV/cm): Average electric field applied between the top and bottom electrodes, calculated as Vpp divided by 500 nm.
Fast Fourier transformed vibrometer signal (dB): The maximum magnitude of the laser vibrometer output signal after FFT performed by the oscilloscope.
Velocity (m/s): The device velocity calculated from the fast Fourier transformed vibrometer signal.
Displacement (nm): The device displacement calculated from the velocity.

Figure2c.csv: Maximum displacement of different devices.

Resonance frequency (Hz): Frequency of the AC excitation applied to the device at which the maximum displacement occurred.
Fast Fourier transformed vibrometer signal (dB): The maximum magnitude of the laser vibrometer output signal after FFT performed by the oscilloscope.
Velocity (m/s): The device velocity calculated from the fast Fourier transformed vibrometer signal.
Displacement (nm): The device displacement calculated from the velocity.

Figure 3 folder

Figure3b.csv: 5th harmonic displacement of monolayer device with different beam lengths, calculated using our COMSOL Multiphysics model.

Beam length (mm): Length of the beam between boundary constraints modeled using COMSOL Multiphysics.
Displacement (nm): Simulated 5th-harmonic beam displacement of the modeled beam under 40 V peak-to-peak AC excitation.

Figure3c.csv: 4th-, 5th-, 6th-harmonic frequencies of monolayer device with different beam lengths, calculated using our COMSOL Multiphysics model.

Beam length (mm): Length of the beam between boundary constraints modeled using COMSOL Multiphysics.
4th harmonic frequency (kHz): Simulated 4th-harmonic beam bending frequency of the modeled beam.
5th harmonic frequency (kHz): Simulated 5th-harmonic beam bending frequency of the modeled beam.
6th harmonic frequency (kHz): Simulated 5th-harmonic beam bending frequency of the modeled beam.

Figure 4 folder

Figure4a_1.csv: Maximum displacement of flexo devices at different temperatures.

Resonance frequency (Hz): Frequency of the AC excitation applied to the device at which the maximum displacement occurred.
Temperature (K): Temperature of the device stage in the vacuum chamber.
Fast Fourier transformed vibrometer signal (dB): The maximum magnitude of the laser vibrometer output signal after FFT performed by the oscilloscope.
Velocity (m/s): The device velocity calculated from the fast Fourier transformed vibrometer signal.
Displacement (nm): The device displacement calculated from the velocity.
Relative displacement: Displacement divided by the Displacement at 295 K.

Figure4a_2.csv: Maximum displacement of piezo devices at different temperatures.

Resonance frequency (Hz): Frequency of the AC excitation applied to the device at which the maximum displacement occurred.
Temperature (K): Temperature of the device stage in the vacuum chamber.
Fast Fourier transformed vibrometer signal (dB): The maximum magnitude of the laser vibrometer output signal after FFT performed by the oscilloscope.
Velocity (m/s): The device velocity calculated from the fast Fourier transformed vibrometer signal.
Displacement (nm): The device displacement calculated from the velocity.
Relative displacement: Displacement divided by the Displacement at 295 K.

Figure4b.csv: Applied electric-field vs displacement of monolayer device at 10 K.

Resonance Frequency (Hz): Frequency of the AC excitation applied to the device at which the maximum displacement occurred.
Vpp (V): Peak-to-peak amplitude of the applied AC voltage.
E-field (kV/cm): Average electric field applied between the top and bottom electrodes, calculated as Vpp divided by 500 nm.
Fast Fourier transformed vibrometer signal (dB): The maximum magnitude of the laser vibrometer output signal after FFT performed by the oscilloscope.
Velocity (m/s): The device velocity calculated from the fast Fourier transformed vibrometer signal.
Displacement (nm): The device displacement calculated from the velocity.

Figure4c_1.csv: Cyclic stability test of the monolayer device at 10 K.

Resonance frequency (Hz): Frequency of the AC excitation applied to the device at which the maximum displacement occurred.
Cycles: Number of operating cycles of the device.
Fast Fourier transformed vibrometer signal (dB): The maximum magnitude of the laser vibrometer output signal after FFT performed by the oscilloscope.
Velocity (m/s): The device velocity calculated from the fast Fourier transformed vibrometer signal.
Displacement (nm): The device displacement calculated from the velocity.
Relative displacement: Displacement normalized by the initial displacement of the device.

Figure4c_2.csv: Cyclic stability test of the monolayer device at room temperature.

Resonance frequency (Hz): Frequency of the AC excitation applied to the device at which the maximum displacement occurred.
Cycles: Number of operating cycles of the device.
Fast Fourier transformed vibrometer signal (dB): The maximum magnitude of the laser vibrometer output signal after FFT performed by the oscilloscope.
Velocity (m/s): The device velocity calculated from the fast Fourier transformed vibrometer signal.
Displacement (nm): The device displacement calculated from the velocity.
Relative displacement: Displacement normalized by the initial displacement of the device.

Figure S5 folder

FigureS5a.csv: Simulation result of a 1-directional electric field along an in-plane line at the 0.4 nm position in the MoS2 layer.

x (nm): x-coordinate of the evaluation point in the model.
y (nm): y-coordinate of the evaluation point in the model.
E-field (V/m): Electric field in the 1-direction at the evaluation point, simulated using COMSOL Multiphysics.

FigureS5b.csv: Simulation result of a 3-directional electric field along an in-plane line at the 0.4 nm position in the MoS2 layer.

x (nm): x-coordinate of the evaluation point in the model.
y (nm): y-coordinate of the evaluation point in the model.
E-field (V/m): Electric field in the 3-direction at the evaluation point, simulated using COMSOL Multiphysics.

FigureS5c.csv: Simulation result of a 11-directional electric field gradient along an in-plane line at the 0.4 nm position in the MoS2 layer.

x (nm): x-coordinate of the evaluation point in the model.
y (nm): y-coordinate of the evaluation point in the model.
E-field gradient (V/m^2): Electric field gradient in the 11-direction at the evaluation point, simulated using COMSOL Multiphysics.

FigureS5d.csv: Simulation result of a 33-directional electric field gradient along an in-plane line at the 0.4 nm position in the MoS2 layer.

x (nm): x-coordinate of the evaluation point in the model.
y (nm): y-coordinate of the evaluation point in the model.
E-field gradient (V/m^2): Electric field gradient in the 33-direction at the evaluation point, simulated using COMSOL Multiphysics.

Figure S6 folder

FigureS6_1.csv: Simulation result of a 11-directional electric field gradient along an in-plane line at the 0.15 nm position in the MoS2 layer.

x (nm): x-coordinate of the evaluation point in the model.
y (nm): y-coordinate of the evaluation point in the model.
E-field gradient (V/m^2): Electric field gradient in the 11-direction at the evaluation point, simulated using COMSOL Multiphysics.

FigureS6_2.csv: Simulation result of a 11-directional electric field gradient along an in-plane line at the 0.3 nm position in the MoS2 layer.

x (nm): x-coordinate of the evaluation point in the model.
y (nm): y-coordinate of the evaluation point in the model.
E-field gradient (V/m^2): Electric field gradient in the 11-direction at the evaluation point, simulated using COMSOL Multiphysics.

FigureS6_3.csv: Simulation result of a 11-directional electric field gradient along an in-plane line at the 0.5 nm position in the MoS2 layer.

x (nm): x-coordinate of the evaluation point in the model.
y (nm): y-coordinate of the evaluation point in the model.
E-field gradient (V/m^2): Electric field gradient in the 11-direction at the evaluation point, simulated using COMSOL Multiphysics.

Figure S7 folder

FigureS7a.csv: 5th-harmonic frequency of mono, bi, trilayer devices with different beam lengths, calculated using our COMSOL Multiphysics model.

Beam length (mm): Length of the beam between boundary constraints modeled using COMSOL Multiphysics.
Monolayer device harmonic frequency (kHz): Simulated 5th-harmonic beam bending frequency of the modeled device with monolayer MoS2.
Bilayer device harmonic frequency (kHz): Simulated 5th-harmonic beam bending frequency of the modeled device with bilayer MoS2.
Trilayer device harmonic frequency (kHz): Simulated 5th-harmonic beam bending frequency of the modeled device with trilayer MoS2.

FigureS7b.csv: 5th-harmonic displacement of mono, bi, trilayer devices with different beam lengths, calculated using our COMSOL Multiphysics model.

Beam length (mm): Length of the beam between boundary constraints modeled using COMSOL Multiphysics.
Monolayer device displacement (nm): Simulated 5th-harmonic beam bending displacement of the modeled device with monolayer MoS2.
Bilayer device displacement (nm): Simulated 5th-harmonic beam bending displacement of the modeled device with bilayer MoS2.
Trilayer device displacement (nm): Simulated 5th-harmonic beam bending displacement of the modeled device with trilayer MoS2.

Figure S8 folder

FigureS8.csv: Displacement induced by various mechanisms, calculated using our COMSOL Multiphysics model.

AC Frequency (kHz): Frequency of the applied AC voltage used in the simulation.
1111-Flexoelectric (nm): Simulated maximum beam bending displacement by 1111-directional converse flexoelectric effect.
1133-Flexoelectric (nm): Simulated maximum beam bending displacement by 1133-directional converse flexoelectric effect.
Piezoelectric (nm): Simulated maximum beam bending displacement by converse piezoelectric effect.
Electromagnetic Stress (nm): Simulated maximum beam bending displacement by electromagnetic stress.
Joule heating (nm): Simulated maximum beam bending displacement by Joule heating.

Figure S9 folder

FigureS9.csv: Maximum displacement of second monolayer device at different excitation frequencies.

AC Frequency (Hz): Frequency of the AC excitation applied to the device.
Fast Fourier transformed vibrometer signal (dB): The maximum magnitude of the laser doppler vibrometer output signal after FFT performed by the oscilloscope.
Velocity (m/s): The device velocity calculated from the fast Fourier transformed vibrometer signal.
Displacement (nm): The device displacement calculated from the velocity.

Sharing/Access information

All data were measured and calculated by the authors using research instruments and COMSOL Multiphysics.
To request for additional or more detailed data, please contact the corresponding author, SungWoo Nam (sungwoo.nam@uci.edu), or the first author, Yeageun Lee (yeageunlee@gmail.com).

Data from: Converse flexoelectric two-dimensional MoS₂ actuator

Data files

Abstract

Description of the data and file structure

Figure 2 folder

Figure 3 folder

Figure 4 folder

Figure S5 folder

Figure S6 folder

Figure S7 folder

Figure S8 folder

Figure S9 folder

Sharing/Access information

Data from: Converse flexoelectric two-dimensional MoS2 actuator

Data files

Abstract

README: Data from: Converse flexoelectric two-dimensional MoS2 actuator

Description of the data and file structure

Figure 2 folder

Figure 3 folder

Figure 4 folder

Figure S5 folder

Figure S6 folder

Figure S7 folder

Figure S8 folder

Figure S9 folder

Sharing/Access information

Data from: Converse flexoelectric two-dimensional MoS₂ actuator