Driving the BP7 Micropump: Signal Control and Electronics

To get the most out of the BP7 micropump, you need more than just power, you need precision. This article explores how piezoelectric actuation works in the BP7, what kind of signals are required, and how proper phase control and driving electronics determine flow performance. Whether you’re prototyping or integrating the pump into an OEM system, understanding signal behavior is key to maximizing the potential of this compact piezo micropump.

Understanding the Fundamentals of Piezo Drive Signals

The BP7 micropump uses piezo-driven diaphragms to create fluid movement. To activate this mechanism, the pump requires:

• Alternating Current (AC) signals, not static voltages.
• Frequencies typically between 100 Hz and 300 Hz. The frequency affects flow rate and pressure output.
• Voltage amplitudes up to 250 Vpp (volt peak-to-peak). These signals are typically offset (e.g., from -50 V to +200 V) to protect the piezo actuators from stress or dielectric breakdown.
• Waveform shapes that influence acoustic behavior and mechanical efficiency. Sinusoidal signals are common, but square or SRS waveforms may be used for different performance characteristics.

The piezo actuators convert electrical energy into diaphragm motion. With 250 Vpp input, they generate a stroke of about 35 μm per cycle. This defines the stroke volume and influences flow rate.

Why Phase Shift Matters

The BP7 contains two piezo actuators. To create continuous, low-pulsation flow, the actuators must work against each other in a 180° phase shift:

• When one actuator expands, the other contracts.
• If driven in phase (0°), the effect cancels out causing poor flow and increased pulsation.

Correct phase alignment is crucial for optimal pump performance, especially in precise or sensitive microfluidic systems.

Visualizing the Signal Behavior

The signal behavior is best understood using visual tools:

• Working cycle diagrams show how alternating piezo motion drives fluid through the internal pump chambers.
• Oscilloscope snapshots demonstrate real-world drive signals with key parameters:
  • Voltage offset (e.g. -50 V to +200 V)
  • Clean sine waveforms
  • Clear 180° phase shift between channels

These tools allow you to verify that your drive system is set up correctly.

Driving Electronics Options

Bartels Mikrotechnik offers a range of solutions to drive the BP7:

1. mp-Labtronix (Desktop Testing)

• Complete control of all signal parameters (voltage, frequency, waveform, phase)
• Software GUI and visualization included
• Best suited for lab use, prototyping, and testing

2. Plug-and-Play Drivers (Modular Systems)

• Compatible with the mp-Multiboard2 system
• Include various voltage variants: mp-Driver, mp-Lowdriver, mp-Highdriver, mp-Highdriver4
• Pre-configured with the correct settings for the BP7
• Designed for scalable or parallel systems

3. Fully Embedded Driver Integration (OEM)

For OEM or productized applications, Bartels’ driver solutions can be custom-integrated into your own electronics.

• Based on the same principles as the drivers mentioned above, but tailored to your system’s needs (e.g. compact form factor, custom connectors, firmware-level control).
• Requires in-depth electronics knowledge but offers maximum flexibility for product development and cost optimization at scale.

Flexible driver solutions for your needs
Whether you need just the electronics, a complete PCB, or fully integrated drivers, our custom solutions can scale to your product and production requirements. Contact us to discuss how we can tailor our driver systems to your project.

Fine-Tuning for Performance

To match your specific system setup, drive parameters can be adjusted:

• Frequency: Higher frequency increases flow up to a performance peak.
• Voltage: Higher voltage expands diaphragm movement and increases stroke volume.
• Load conditions: Viscosity and backpressure influence flow. Drive signals must compensate accordingly.
• Closed-loop feedback: By integrating flow or pressure sensors, signals can be dynamically adjusted for consistent, regulated performance.

Always stay within the rated ranges (up to 250 Vpp and recommended frequency bands) to protect the piezo elements and electronics.

Safety Considerations

Because piezo systems operate with high voltages, you should follow best practices:

• Insulate all exposed conductors
• Maintain a common ground between devices
• Respect voltage ratings of all components in your system

By understanding and carefully managing the electronic control of the BP7 micropump, you can harness its full potential in your microfluidic applications. For detailed specifications, application notes, and support, refer to Bartels Mikrotechnik’s official resources or contact their technical support team.

Conclusion

The BP7 micropump relies on precise, alternating drive signals for effective performance. Understanding the importance of voltage, waveform, frequency, and especially the 180° phase shift, allows you to fine-tune the system for maximum flow stability. Whether you’re using pre-configured hardware or designing a custom setup, choosing the right driving approach directly influences how well the BP7 integrates into your microfluidic application.

Need help choosing the right electronics for your setup?