Analysis of the basic working principle of piezoelectric valves

Piezoelectric valves, as high-performance control components, have been widely used due to their advantages of fast response speed, high precision, and low energy consumption. This article will delve into the basic working principles of piezoelectric valves and understand the scientific principles behind this technology.

 I. Piezoelectric Effect: The Physical Basis of Piezoelectric Valves

The core of a piezoelectric valve lies in the piezoelectric effect, a special physical phenomenon where certain crystalline materials, when subjected to external forces, exhibit electrical polarization, i.e., a charge distribution appears on the crystal surface. Conversely, when an electric field is applied to these materials, they also deform. This mutual conversion between mechanical energy and electrical energy is the basis for the operation of piezoelectric valves.

Piezoelectric materials mainly include piezoelectric crystals (such as quartz, lithium niobate) and piezoelectric ceramics (such as lead zirconate titanate, PZT). Among them, piezoelectric ceramics, due to their ease of processing and strong performance controllability, have become the most commonly used materials in piezoelectric valves.

 II. Structural Composition of Piezoelectric Valves

Piezoelectric valves typically consist of several parts: a valve body, a piezoelectric actuator, a control circuit, and a sealing component. The valve body defines the fluid passage, while the piezoelectric actuator deforms according to the control signal, thereby changing the opening and closing state of the valve port and achieving precise control of fluid flow.

The piezoelectric actuator is the core component of the piezoelectric valve. It is made of piezoelectric material and, through a specific electrode configuration, can rapidly expand or contract under the action of an electric field. This minute deformation is converted into a large movement of the valve core through a mechanical amplification mechanism (such as a lever or diaphragm), achieving effective switching of the fluid path.

III. Working Principle: Fluid Control Driven by Electric Field

When a voltage is applied to the piezoelectric actuator, the positive and negative charge centers inside the piezoelectric material shift, causing the material to elongate or shorten along the direction of the electric field. This process is extremely rapid, usually completed within microseconds, giving the piezoelectric valve an extremely high response speed.

Taking a two-position, two-way piezoelectric valve as an example, when the control signal is high, the piezoelectric actuator elongates, pushing the valve core away from the valve seat, and the fluid passage opens; when the control signal is low, the piezoelectric actuator contracts, the valve core returns to the valve seat, and the fluid passage closes. By precisely controlling the application and removal of voltage, continuous adjustment or on/off control of the fluid flow rate can be achieved.

IV. Performance Characteristics and Application Advantages

The reason piezoelectric valves are favored in many fields is due to their significant performance characteristics:

1. Fast Response: Due to the rapidity of the piezoelectric effect, the response time of piezoelectric valves is extremely short, suitable for high-frequency, fast-switching control systems.

2. High Precision: Through precise voltage control, minute adjustments to the fluid flow rate can be achieved, meeting high-precision control requirements.

3. Low Power Consumption: The electrical energy required for piezoelectric valve operation is minimal, and almost no energy is consumed in the non-working state, which is conducive to energy saving and emission reduction.

4. No Magnetic Interference: Piezoelectric materials do not contain magnetism and will not be affected by external magnetic fields, making them suitable for occasions with complex electromagnetic environments.

5. Corrosion Resistance: Using appropriate materials, piezoelectric valves can withstand various corrosive media, expanding their range of Applications.

Based on its unique piezoelectric effect, the piezoelectric valve achieves high-precision and rapid control of fluids through electric field driving. Its compact structure and superior performance make it an indispensable part of modern automated control systems. With the continuous advancement of materials science and micro-nano manufacturing technology, the performance of piezoelectric valves will be further improved, and their Applications will become even more extensive.