A piezoelectric ceramic that converts electrical energy to mechanical energy is known as a piezoelectric actuator. When an electrical voltage is applied, the piezo actuator deforms to generate displacement. Piezoelectric actuators come in a range of shapes, including disc actuators. When voltage is applied to the piezo ceramic disc, the piezoelectric material contracts or expands, deforming the disc. The center of the disc deforms the most forming a dome, and direction of displacement depends on how the voltage is applied, in relation to the polarity of the faces of the piezo disc. One side of the disc expands like a dome, while the other side contracts like a bowl. Amplifying this deformation is the driving force to generate displacement.

Piezoelectric disc actuators can be constructed as either a unimorph or bimorph. Unimorph piezo actuators are constructed of one active layer of piezo ceramic bound to a passive metal substrate for support. Unimorphs deform in a single direction when activated to generate the desired mechanical output. Bimorph piezo actuators are constructed of two active piezo ceramic layers with a passive metal substrate sandwiched in between. The passive substrate layer strengthens piezo elements which can be fragile, since piezo has all the physical properties of ceramic thus the name piezo ceramic.

Piezo is metallized, either through a physical or chemical process, and then polarized. Metallization is only on the faces of the piezo, not on the side. In both unimorphs and bimorphs, the layer(s) of piezoceramic material are bonded with a substrate. For some special applications, bimorphs do not have a substrate sandwiched in between the two layers of piezo, instead the two pieces of PZT discs are bonded directly to each other. The substrate acts as a base and stabilizer for the disc actuators and can be any material, conductive or nonconductive. During the deformation process, a substrate holds the piezoelectric product together and prevents it from falling apart.

The substrate in this case (disc piezo actuator) is also very important. When the displacement is being blocked, a force is generated.  The stiffer the substrate, the higher the force it will generate, however the smaller the displacement will be. So, when designing a disc piezo actuator, choosing the right substrate will be also crucial based on the application.

Piezo disc actuators, unimorph and bimorph alike, can displace in one direction and/or both directions depending on your applications when DC voltages are applied. Or they can simply just vibrate at the designed frequency when AC Voltages are applied.

We offer a variety of piezoelectric discs. Shape, finish, material, dimensions, and performance levels can all be customized! Piezo Direct’s discs are suitable for numerous applications. Unsure what you need? Contact us! Piezo Direct is more than happy to work with you to design custom piezoelectric products to meet your application requirements.

Piezo Disc
Piezo Ceramic Actuators
Piezo disc actuator
Piezo disc actuators

If none of these products match your requirements, click here to learn more about working with our engineers to build a custom piezo component.

Features

Piezoelectric disc actuators are small, thin, lightweight, quiet, extremely efficient with low power consumption, and have fast response times. They are widely used in a broad range of applications, especially air and fluid pumps, valves, and in commercial household applications as well. Piezo actuators do not require lubrication for operation and can function in harsh vacuum and cryogenic environments.

For Piezo disc actuators, the displacement is directly proportional to the voltage applied. In most of the valve applications, the flow rate can be accurately controlled and adjusted, making disc actuators suitable for high precision applications, such as in medical and industrial settings. Their small nature does not negatively affect performance, and these unimorph and bimorph disc actuators can generate large displacement.

Applications

The most common application for piezo ceramic discs is in air and fluid pumps. In the example of a fluid pump, as the actuator bends, the rapid deformation causes a difference in pressure between the outside of the chamber and the inside of the chamber, forcing the fluid to move through the chamber. When the current is created in the fluid and subsequently released, the piezo disc goes back to its original state. This can be seen in pumps for fish tanks, automatic espresso machines, propane stoves, and much more. When the piezo element in the pump receives the electrical voltage, the unimorph or bimorph actuator deforms to generate movement through the pump. Liquid cooling systems for CPUs computer, LED lights, etc. also utilize piezoelectric discs. To cool CPUs, disc actuators move coolant through the system and to the radiator which helps it cool.

Printer bulk ink supply systems follow the same principle as liquid pump systems. The electrical signal to begin printing bends the piezo disc actuator and pushes the precise level of ink needed into the chamber to be printed.

Medical equipment, such as blood pressure monitors and insulin dosing machines, use piezo disc actuators for precision. The displacement of piezoelectric actuators can be very fine, so monitor readings and medicine dosing can be extremely accurate with the use of piezo discs.

Piezo disc actuators are very commonly used for sound production and use AC power instead of DC power. Their powerful displacement combined with rapid vibration makes for a clear sound with potent sound pressure. This can be observed in products like fire alarms. In regard to sound production, disc actuators carry huge power in terms of force and are the most common piezoelectric ceramic utilized for sound production applications. Sound-generating buzzers, alarms, and buttons implement piezo actuators to bend or deform at a signal and create a sound. This can be seen in timers, clocks, microwaves, car keys, PIN pads, and alarms and buzzers.

Automatic lubricant supply systems for precision instruments greatly benefit from the accuracy and precise displacement of piezo ceramic disc actuators. Lubricating systems are essential for the smooth operation of rotating machinery parts. Valves using piezo disc actuators are able to release the exact amount of lubricant needed since width and duration of the valve opening can be easily controlled through the displacement of the piezo disc and its duration, allowing a precisely defined amount of lubricant to be released.

Specifications

Model

D x T
(mm)
Capacitance 
(nF)

@1V, 100 Hz

Displacement
(µm)
155Vp-p

QDTA27-0.5-1

27 dia. x 0.5

PZT: 24 dia. x 0.3

55 ± 15%50 – 80
QDTA41-0.6-141 dia. x 0.6

PZT: 36 dia. x 0.3

115 ± 15%70 – 110
QDTA55-0.55-155 dia. x 0.5
PZT: 48 dia. x 0.3
245 ± 15%130 – 170

Note: Custom size and specifications available upon request.

Recommended Operative Conditions

Operating Temperature: -10℃~+70℃
Operating Voltage: 100 VDC~115 VDC
Maximum Voltage: 120VDC
Operating Frequency: 50Hz~60Hz