Constant-Power versus Constant-Voltage Actuation in Frequency Sweeps for Acoustofluidic Applications

Area of Science:

• Acoustofluidics
• Microfluidics
• Particle Manipulation

Background:

• Acoustofluidic resonance frequencies are crucial for understanding particle behavior in microchannels.
• Determining these frequencies accurately is essential for applications like particle sorting and manipulation.
• Existing methods using constant voltage or power have limitations.

Purpose of the Study:

• To compare three different methods for supplying power to piezoelectric transducers during frequency sweeps.
• To evaluate the suitability of each method for reproducible characterization of acoustofluidic devices.
• To identify the most reliable approach for determining acoustofluidic resonance frequencies.

Main Methods:

• Simulated and measured the response of a piezoelectric transducer under three conditions: constant input voltage, constant transducer voltage, and constant transducer power.
• Compared the results obtained from each method.
• Analyzed the influence of amplifier impedance and transducer impedance on the measurements.

Main Results:

• Constant input voltage is affected by amplifier and wiring impedance, making it unsuitable for reproducible characterization.
• Constant transducer voltage favors resonances at low impedance, potentially missing secondary resonances.
• Constant average power dissipation provides the most reliable results, identifying primary and secondary resonances.

Conclusions:

• Constant power supply is the most accurate and reliable method for characterizing acoustofluidic resonance frequencies.
• This method allows for the identification of both primary and secondary resonances, offering a comprehensive understanding of the device's acoustic properties.
• Researchers should adopt the constant power method for precise and reproducible acoustofluidic device characterization.