Application Cases

【Overview】
In this study, the Aigtek ATA-2021B high-voltage amplifier was used to build an acoustic streaming experimental platform for aggregating iron powder. Flexible sensors are a key technology in intelligent systems, but traditional methods for preparing their dielectric layers struggle to precisely control the distribution of iron powder, limiting sensor performance improvement. Acoustic streaming technology, with its advantages of non-contact operation and high precision, enables precise arrangement of particles in liquid media. This study proposes a method for controlling the Fe/silicone composite dielectric layer based on this technology. First, COMSOL simulations were conducted to analyze the driving effect of acoustic streaming on iron powder in liquid silicone at a frequency of 75.49 kHz. Subsequently, experiments using liquid silicone with 25 wt% iron powder verified the effectiveness of the technology, achieving controlled morphology of the composite dielectric layer.

Experiment Name: Acoustic Streaming Experiment for Aggregating Iron Powder

Experiment Principle:
A signal generator and a power amplifier drive an ultrasonic transducer, causing an ultrasonic needle to vibrate at a frequency of 75.49 kHz within liquid silicone containing 25 wt% iron powder. This generates a specific acoustic streaming field. The driving force of the acoustic streaming directs the iron powder to aggregate toward the ultrasonic needle region. Simultaneously, the correlation between the vibration amplitude of the ultrasonic needle and the influence range of the acoustic streaming enables precise control over the conductive particle distribution and surface morphology of the Fe/silicone composite dielectric layer.

Experimental Block Diagram:

Experimental Setup Photos:

Experimental Procedure:
First, an acoustic streaming experimental platform was built, consisting of a signal generator, a power amplifier, and an ultrasonic transducer. The ultrasonic needle was bonded to the metal excitation surface of a Langevin transducer and inserted into liquid silicone containing 25 wt% iron powder. The operating frequency of the ultrasonic needle was set to 75.49 kHz, and the output voltage of the signal generator was set to 10 V. The amplification factor of the power amplifier was adjusted to change the voltage across the ultrasonic transducer and the amplitude at the excitation point P of the ultrasonic needle. After powering on, the aggregation process of the iron powder in the liquid silicone was observed at different time intervals. Once the aggregation stabilized, the power was turned off. Finally, the relative permittivity of the Fe/silicone composite dielectric layer, controlled by the acoustic streaming, was measured, and the relationship between the vibration amplitude of the ultrasonic needle and the influence range of the acoustic streaming was analyzed.

Application Directions:

• Fabrication of high-performance flexible capacitive sensors

• Wearable health monitoring devices

• Robotic tactile systems

• Composite material control for other flexible electronic devices

• Medical bionic sensing devices

Advantages of Aigtek Amplifiers in This Application:

1. Wide bandwidth and high slew rate – Precisely match the operating frequency to ensure stable excitation of the acoustic streaming field.

2. High voltage output capability – Provide sufficient driving power to generate the required mechanical vibration amplitude in the ultrasonic needle.

3. Low distortion and high output stability – Ensure repeatability and consistency of the acoustic streaming field during long-duration aggregation experiments.

Recommended Product: ATA-2000 Series High-Voltage Amplifier

Specifications and Parameters of ATA-2000 Series High-Voltage Amplifier

Figure: ATA-2000 Series High-Voltage Amplifier Specifications and Parameters