Application Cases

Experiment Name: Fabrication and Electromechanical Response Characterization of Arrayed Micro-Actuators

Research Direction:
Biomechanics and Bionics, Ionic Electroactive Polymer (EAP) Materials, Design and Fabrication of Flexible Actuators

Experiment Objective:
This experiment first designs and fabricates a micro-actuator array based on ionic EAPs, intended for dynamic mechanical stimulation of two-dimensionally cultured cells. It introduces the principle design, material selection, and fabrication process of this arrayed micro-actuator, followed by microstructural and electrical characterization of the material. A testing platform is established to evaluate the electroactive deformation performance of the micro-actuator (qualitative observation and quantitative characterization). Parametric experiments are also conducted by varying the actuator dimensions to further verify the reliability of the fabrication method.

Testing Equipment:

1. Microstructure: Scanning electron microscope, ion sputter coater

2. Electrical Performance: Sheet resistance tester

3. Mechanical Performance: Atomic force microscope, micro-force sensor, analog signal transmitter

4. Electroactive Deformation: Optical microscope, laser displacement sensor, three-axis displacement clamping platform

5. Data Acquisition & Excitation: Industrial PC, data acquisition card, power amplifier (Aigtek ATA-304)

   
   

Figure 1: Electroactive Deformation Performance Testing Platform

Experimental Procedure:
The electroactive deformation performance testing platform uses LabVIEW to generate waveforms such as sine and square waves (frequency from DC to several hundred Hz, amplitude <10 V). These signals are output via a data acquisition card and converted into driving voltage by a power amplifier (Aigtek ATA-304). The three-axis displacement clamping platform (with copper foil affixed as electrodes) secures the specimen and allows adjustment of its relative position to the sensor.

For sensing, leads are drawn from the electrodes of the clamping platform to the data acquisition card to synchronously capture the driving voltage (verifying consistency with set values). The material is fixed using two copper rings, and a laser displacement sensor vertically aligns with the center of the micro-actuator to measure real-time lateral displacement, characterizing out-of-plane deformation.

Data acquisition is performed by the data acquisition card transmitting signals to the industrial PC for recording. Prior to testing, signal input channels and the reference single-ended wiring mode must be configured. The sampling frequency must satisfy the Nyquist theorem (greater than twice the maximum frequency of the measured signal). Displacement calibration establishes a conversion relationship where the actual displacement is twice the analog voltage value; voltage calibration requires no additional setup. The testing environment is maintained at 15–25 °C and 40–50% RH. The platform also includes a blocking force sensing unit and a response current sensing unit.

Experimental Results:
Using laser cutting technology, a 5×5 circular hole array with a diameter of 1.5 mm was fabricated on a supporting substrate membrane. A 5×5 ionic flexible micro-actuator array was successfully fabricated with Nafion as the core layer and PEDOT:PSS as the electrode layer. SEM characterization showed that the electrode layer was tightly bonded to both the core layer and the substrate membrane, exhibiting a continuous and dense structure, ensuring operational stability.

The surface resistance of PEDOT:PSS outside the holes was approximately 6 Ω/sq, while the surface resistance of the micro-actuators on the holes was approximately 4 Ω/sq, supporting electroactive actuation performance. Electroactive deformation tests demonstrated that the array could produce regular, controllable, and rapid out-of-plane deformation under relatively low charge excitation. The deformation was dependent on both voltage amplitude and frequency. Under sinusoidal voltage, the maximum displacement reached approximately 67 μm; under DC voltage, it was approximately 63 μm. Parametric experiments further validated the reliability of the design concept and the reproducibility of the fabrication method.

Product Recommendation: ATA-304C Power Amplifier

Figure: ATA-304C Power Amplifier Specifications and Parameters

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