Analysis of the basic working principle of piezoelectric valves
Release time:
2025-03-17 10:15
Source:
Leica Technology
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.
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How can daily maintenance help extend the service life of a valve body?
As a precision component that operates at high frequency, the precision dispensing valve requires scientific daily maintenance to extend its service life and maintain dispensing accuracy. Shenzhen Laike Technology has compiled the following key maintenance points for you: Daily cleaning is crucial and should not be overlooked. After finishing work, promptly remove any residual adhesive from the exterior of the valve body, especially around the nozzle and plunger area. Once cured, adhesive can cause blockages or wear, affecting subsequent use. It is recommended to gently wipe with a suitable cleaning solvent, taking care not to damage the seals. Regularly inspect sealing components—seals and other parts will naturally degrade over time during prolonged operation. We recommend checking their condition periodically based on usage frequency. If you notice signs of hardening or wear, replace these components promptly to prevent adhesive from seeping into the valve body and causing more serious damage.
The stringing issue during the dispensing process is often closely related to fluid properties, equipment parameters, and process settings. Drawing on years of industry experience, SZLKTE has compiled and optimized key points for you: Fluid temperature control is crucial. Proper heating can reduce the viscosity of the adhesive, improve its flowability, and minimize stringing and trailing. SZLKTE’s dispensing valves can be equipped with precision temperature-control modules to ensure that the fluid remains in a consistently stable working state. The back-suction parameters must be finely adjusted. The negative-pressure back-suction applied at the moment the glue dispensing stops can effectively cut off the adhesive flow, preventing dripping and stringing. We recommend gradually adjusting the amount and speed of back-suction according to the adhesive’s viscosity until you find the ideal balance.
SZLKTE takes a multi-dimensional approach to ensure zero errors and long service life for its products even under high-speed, continuous operation. The piezoelectric valve series employs piezoceramic actuation technology; its non-contact drive design eliminates mechanical wear common in traditional solenoid valves, enabling a service life of over one billion cycles. At the same time, these valves deliver millisecond-level response times, completely eliminating trailing and stringing issues. The needle valve KC-9870, on the other hand, features a specially engineered, wear-resistant material for its needle component, offering exceptional resistance to abrasion and corrosion. Even in industrial environments with prolonged operation, this valve maintains outstanding stability. Moreover, its components can be quickly disassembled and maintained, significantly reducing production downtime.
Contact Dispensing vs. Non-Contact Jetting Valves: How Should You Choose for Micron-Level Processes?
Contact dispensing involves the needle making physical contact with the substrate surface to apply the fluid. Its main advantage lies in its strong adaptability to high-viscosity fluids and relatively controllable dispensing process. However, since it requires coordinated movement along the Z-axis, the dispensing speed is limited. Additionally, there is a risk of the needle colliding with and damaging the workpiece or deforming the needle itself. Therefore, careful evaluation is necessary when applying this method in miniaturized packaging scenarios. In contrast, non-contact jetting valves use a driving mechanism to rapidly spray adhesive onto the workpiece surface without any physical contact between the needle and the substrate. This feature makes them ideally suited for substrates with uneven surfaces or those that are fragile. They excel in micron-scale processes such as bottom-fill applications for chips and precision coating. The jetting method eliminates the need for Z-axis movement, significantly boosting production efficiency while also avoiding common issues associated with contact dispensing, such as stringing and trailing.
The stability of the piezoelectric valve dispensing process directly determines product quality. Common issues such as uneven dispensing, stringing, and glue leakage can be effectively addressed through parameter adjustments and optimized matching. Laike’s piezoelectric valves support multi-level parameter adjustments, enabling precise matching of pressure, injection frequency, and nozzle aperture according to the specific characteristics of different fluids.
Blocking the hole is Piezoelectric valve The most common failures in dispensing operations are often caused by fluid solidification, residual impurities, and nozzle wear, which directly affect dispensing accuracy and efficiency. Given the structural characteristics of piezoelectric valves, these issues can be addressed in three steps: “diagnosis—cleaning—inspection.” First, stop the machine and visually inspect the nozzle for obvious glue deposits or foreign objects, determining whether the blockage is temporary or a persistent issue caused by nozzle wear.
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