Measurement Data of Two Coupled MEMS Resonators Used as Acoustic Sensors

This dataset contains experimental measurement data from two coupled MEMS resonators used as an acoustic sensor.
The data are organized into six zipped folders, each corresponding to a specific measurement analysis.

Unless stated otherwise:

• MEMS time-series files are stored in .mat format.

• Sampling frequency of MEMS measurements: 125 kHz.

• In every .mat file:

  • Row 1 = resonator with higher listed frequency

  • Row 2 = resonator with lower listed frequency

1. Sensitivity_analysis_measurements.zip

Subfolder (I): 3630_3790_Hz_sweep_high_resolution_recheck_2/

Time-series measurements of two coupled resonators with natural frequencies 3790 Hz and 3630 Hz.

• Sampling frequency: 125 kHz

• Response to a 1–10 kHz acoustic sweep

• Filename example:
  Cantilever_3790_Hz_3630_Hz_DC_0xfffff667_cf_0.5_excitation_0.01.mat

Parameter meaning:

• 3790_Hz → Resonator 1 (row 1)

• 3630_Hz → Resonator 2 (row 2)

• DC_0xfffff667 → DC = −150 mV (2’s complement, hexadecimal)

• cf → coupling strength

• excitation → signal-generator driving voltage

Subfolder (II): Input_sound_sweep_1k_10kHz_2/

Microphone recordings of the loudspeaker sweeps.

• Sampling frequency: 44 kHz

• Files stored as .wav

• Example:
  Old_speaker_amplitude_frequency_1000-10000Hz0.01.wav

Notes:

• Sweep range: 1–10 kHz

• Driving amplitude: e.g., 0.01 V

• Convert voltage to sound pressure (Pa) by:

  Sound pressure (Pa) = voltage_from_wav / 0.0149

Included MATLAB code

File: Sensitivity_determining_plot_code.m

• Computes peak-to-peak amplitudes of MEMS responses

• Converts microphone recordings into pressure

• Computes sensitivity (V/Pa)

• Plots sensitivity vs. coupling strength and input amplitude

• Uses the relation:

  gamma_12 * gamma_21 = (cf / 2)^2
  

  due to FPGA buffer-board scaling and symmetric coupling.

➡️ Run the script directly to reproduce sensitivity plots.

2. Frequency_tunability_analysis_measurements.zip

Subfolder: Sweep_near_bifurcation_Negative_to_positive_af/

Time-series responses to a 3–4.5 kHz acoustic sweep with varying feedback and coupling parameters.

Example filename:
Cantilever_3790_Hz_3630_Hz_DC_0xfffff667_af1_-0.5_af2_-0.5_cf_1.375.mat

Parameter meaning:

• af1 → feedback strength of resonator 1

• af2 → feedback strength of resonator 2

• cf → coupling strength

Included MATLAB code

File: Frequency_analysis_3D_plot_code.m

• Computes FFT for all (af1, af2, cf) combinations

• Extracts resonance frequencies from FFT maxima

• Generates 3D colormap plots of resonance vs. feedback

• Also plots effective coupling vs feedback

• Values in plots are halved due to the FPGA buffer board.

➡️ Run the script to reproduce resonance-frequency maps.

3. Frequency_tunable_Regime_1_DC_vs_C_crit.zip

Measurements in Regime 1 (frequency-tunable), no sound excitation.

Example filename:
Cantilever_3630_Hz_3790_Hz_DC_100mV_Cf_0.5.mat

Includes measurements for varying:

• DC offset

• Coupling strength (Cf)

Included MATLAB code

File: Amplitude_vs_Cf_different_DC_3630Hz_3790Hz.m

• Plots amplitude vs. coupling strength for several DC values

• The critical coupling CcritC_{\text{crit}}Ccrit is defined as the value of Cf where the amplitude exceeds 100 mV

➡️ Run the script to extract amplitude vs Cf for different DC values.

4. Frequency_tunable_Regime_2_DC_vs_C_crit.zip

Same structure as Regime 1, but corresponding to Regime 2 (another frequency-tunable region).

Included MATLAB scripts

Run the script corresponding to each resonance pair:

• Amplitude_vs_Cf_different_DC_3630Hz_3730Hz.m

• Amplitude_vs_Cf_different_DC_3630Hz_3790Hz.m

• Amplitude_vs_Cf_different_DC_3790Hz_3730Hz.m

➡️ Run the script to extract amplitude vs Cf for different DC values.

5. Frequency_untunable_Regime_DC_vs_C_crit.zip

Measurements from the frequency-untunable regime, with varying DC and coupling strength.

Included MATLAB scripts

• Amplitude_vs_Cf_different_DC_3630Hz_4380Hz.m

• Amplitude_vs_Cf_different_DC_5190Hz_3630Hz.m

• Amplitude_vs_Cf_different_DC_5190Hz_4380Hz.m

➡️ Run the script to extract amplitude vs Cf for different DC values.

6. Frequency_response_different_regimes_before_bifurcation.zip

Contains .fig files showing frequency responses of the coupled resonators just before Hopf bifurcation in:

• Frequency-untunable regime

• Frequency-tunable regime 1

• Frequency-tunable regime 2

These figures illustrate how the system behaves in the non-linear regime near the bifurcation point.