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Approaching Piezo - CoreMorrow Piezo Objective Scanner

By 22.6.2022         Phone:+86-18946006379       Mail Now Send Mail   Post Comments

The name of Piezo Objective Scanner is actually derived from the combination of its driving principle and application purpose. "Piezo" refers to its driving principle, that is to use piezo ceramics as driving source to generate movement. And "objective scanner" is its application purpose, to adjust the movement with the carrying lens. But in general, the piezo objective scanner itself does not contain any lens, it can carry different types of lens according to the actual use requirements.

Piezo objective scanner is also called Piezo Objective Driver.

What is a Piezo Objective Scanner?

Piezo objective scanner is specially designed for objective focusing microscopy. Configured with non - regressive flexible hinge parallel steering mechanism, it is small compensation quantity and high focusing stability. Piezo objective scanner with microscopic inspection/measurement or observation device, drives the objective lens to focus and adjust Z-axis motion. It can be used with a variety of high resolution microscopes to improve the focusing accuracy of the objective to nanometer.

Category of Piezo Objective Scanners

Piezo objective scanner can be generally divided into three types: high dynamic , large stroke , and high load.

1) High dynamic piezo objective scanner

High dynamic piezo objective scanner is suitable for dynamic operation applications, such as the Coremorrow P72 series with compact structure, can achieve a stroke of 100μm displacement. A variety of threaded tooth connectors are available for easy integration with other optical microscopes. It has been widely used in optical scanning, confocal microscopy and other fields, because of its no-load resonant frequency up to 350Hz, and can carry 200g load to do high-speed precision motion.

P72 piezo objective scanner & frequency / load curve

2) Large stroke piezo objective scanner

Normally, the travel of the piezo objective scanner is about 100μm, but the travel of the large-stroke version can be up to 1mm. For example, you can choose 200μm, 500μm and 1mm linear motion range on Z axis motion with Coretomorrow P73 series, which also has the flexible hinge mechanism, with no friction, good linear motion and high closed-loop positioning accuracy. The separate thread adapter design is suitable for many types of microscopes.

P73 piezo objective scanner & displacement range

3) Piezo objective scanner with high load

In general, piezo objective scanner has a load capacity of 200g, which is based on the weight of ordinary objective. However, this bearing capacity is far from enough for the industrial application of the objective lens, because the weight of the industrial objective lens can be up to 500g, which requires the corresponding large load piezo objective scanner. Coremorrow P76 series are designed for high-load, high-precision, large-aperture objective to achieve ultra-fast step time in modern high-resolution microscopic applications, such as wafer cutting applications. P76 series has a load capacity of 500g, which is compatible with large field of view objectives commonly used in multi-photon and confocal microscopic applications. P76 piezo objective scanner can be matched with Zeiss, Nikon, Olympus, Leica and other standard lenses. It can also be used in conjunction with a manual adjustment table through an adapter.

P76 piezo objective scanner & frequency / load curve

Characteristics of Piezo Objective Scanner

Nanometer precision & Millisecond response

The piezo objective scanner is characterized by its ultra-high precision motion and ultra-fast response speed. How much is this ultra precision? Resolution≤1nm! The resolution of the piezo objective scanner can up to 1 nanometer (nm, 1nm=10^-9m).

And how fast is ultra-fast response? < 1ms! From the moment of controlling the movement of the piezo objective scanner, to the moment of the piezo objective scanner moves to the specified displacement, it can be as fast as 1ms (MS, 1MS =0.001s), that is, in one thousandth of a second, it can complete the linear movement of a certain displacement.

Separate thread adapter for easy installation

Separable thread adapter, compatible for a variety of microscope, widely used in microscopic imaging, two-photon microscope and other fields.

Coremorrow piezo objective scanner is connected with the objective lens through an adapter, which quickly locks the objective lens in the desired position. Thread teeth is available, such as M27*0.75, M26*0.75, M26*1/36", M25*0.75, W0.8*1/36", etc. Thread sizes can be customized for easy integrated installation with the microscope, which can also match Zeiss, Nikon, Olympus, Leica and other standard lenses.

Optional Z/multi axis movement and appearance structure

Piezo objective scanner is available for single-axis and multi-axis. The single-axis is usually used in the Z-axis.
(Note: If X is used, it should be specially noted when ordering. We will adjust the internal structure to suit your application.) Multi-axis versions is also available, such as the XYZ axis motion. In addition, the appearance and structure can also be customized according to the application equipment.

Vacuum compatible

Vacuum version is available to facilitate microscopic imaging operations in a vacuum environment. Vacuum version piezo objective scanner adopts vacuum compatible piezo ceramics, housing, connectors and so on .

Applications of Piezo Objective Scanner

The high precision and fast response characteristics of Coremorrow piezo objective scanner have been widely used in optical systems, from microscopic imaging, optical detection to laser material processing, and white light interference regulation, etc.

1. Laser wafer cutting

The principle of laser wafer cutting is to focus the laser through a lens, and then the position of the focus is precisely adjusted by the piezo objective scanner, so that the focus is precisely positioned at the part of the wafer to be cut. The temperature of the part to be cut rises rapidly, and then it is melted or vaporized. With the laser and the relative movement of the cutting material, a plurality of points is formed on the cutting material.

The robust design of the P76 provides very fast stabilization time and scanning frequency, even when carrying several hundred grams of objective lens. The rotating symmetrical arrangement of multiple piezoelectric actuators and the optimized design of deflection and lever elements ensure the stiffness, excellent steering accuracy and dynamics. Coremorow piezo objective scanner achieved mass production, and applied to a number of domestic laser cutting equipment manufacturers.

2. Improve the focusing accuracy of ordinary microscope

Normally, there are two handwheels on both sides for coarse tuning and fine tuning. With the rotation of the handwheel, the objective lens or the loading platform of the microscope will move up and down. Handwheel adjustment is very convenient, but there are precision limits, the precision of fine tuning can only reach 0.002mm( 2μm). For fine-tuning that requires accuracy of a few nanometers, handwheel adjustment becomes helpless.

The focusing precision of microscope imaging can be greatly improved by adopting the piezo objective scanner produced by Coremorrow. For example, P72 is compact and easy to integrate. It has a fine stroke of 100μm and a resolution of 2.5nm, and is easy to assemble, just to be installed on the objective lens, as shown in the image above.

The tuning distance of the piezo objective scanner can be controlled by the piezo controller. The variable output voltage of the piezo controller corresponds to the displacement of the piezo objective scanner from zero to full stroke, and the two are in a linear relationship. The tuning distance of the piezo objective scanner can be controlled by changing the size of the variable output voltage of the piezo controller.

3. Super-resolution microscopic imaging

Microscopic optical imaging refers to the technology of magnifying images of tiny samples from the visible light reflected through or from samples. Super resolution (SR) microscopy is a broad concept to describe the emerging optical microscope. Although conventional optical microscopes can achieve 100 nanometers resolution , this ultra-resolution technology can achieve higher resolution even up to tens of nanometers. The SR microscope uses specific fluorescent probe properties to separate the photons emitted by two closely spaced fluorescent sources so that they can be imaged separately, avoiding diffraction limits and allowing the dynamic effects of cells in the nanoworld to be observed.

New super-resolution techniques, such as stimulated emission loss microscopy, light-activated localization microscopy and random optical reconstruction microscopy, have reduced resolution from 100-200 nm to even lower. Piezo objective scanners with nanometer resolution is ideal for these applications. The alignment of the microscope and the sample stand requires accurate and rapid movement. Piezo objective scanner based on high resolution piezo ceramics can provide unique ultra-precision technology support.

4. Laser lithography, optical disk data storage

Laser lithography is one of the most mainstream methods of nano-lithography, especially for photonic crystals. The development of metamaterials largely depends on the progress of laser lithography. Nano structured devices will become the basis of integrated circuits in the future.

The photolithography process means that the photolithography substrate placed on the electric platform rotates and moves along with the electric platform, and the acoustooptic modulator controls the strength of light beam to expose the photolithography at varying doses. Usually, the positioning accuracy of the electric platform reaches micron or submicron magnitude. However, the pitch error and deviation of the electric platform caused by inertia, static friction and loosening will directly affect the performance of the system and the quality of the lithographic elements. In laser lithography, Coremorrow piezo objective scanner and Piezo nano stages have been successfully applied.

Coremorrow piezo objective scanner adopts flexible hinge mechanism based on the elastic deformation of solid, no rolling and sliding part, with zero friction, high precision, and has high stiffness and bearing capacity. More importantly, the positioning accuracy can achieves nanometer or even sub-nanometer. With its nanometer precision, stable performance and convenient operation, Coremorrow piezoelectric objective scanner has become the ideal choice for scanning motion platform in lithography equipment.

5. White light interference and 3D end face detection

White light interference technology takes visible light as the light source. The white light emitted by the light source reflects half of the light intensity in the semi-transmitted optical plane after passing through the interference objective lens, and the other half of the light intensity is transmitted and irradiated on the surface of the measured object and reflected again into the interference objective lens, which interferes with the reflected light in the original optical plane. With Coremorrow P73 series piezoelectric objective scanner, the accuracy can achieve nanometer resolution, vertical scanning height can reach 1000μm.

At present, optical interference is commonly used to measure the optical fiber end face. Optical interference is based on the coherent light encounter in space, which enhance or weaken in different areas, forming a stable strong and weak distribution. The 3D interferometer system is designed on this principle. interference fringes can be observed by CCD camera, Coremorrow P76 piezo objective scanner is used to move the interference objective lens to produce phase movement, the image measured by CCD camera is transmitted to the computer by image card for analytical processing.

Piezo objective scanner is widely used with basically similar principles, to achieve fast and accurate step adjustment. , as long as there is an objective in the application scene, piezo objective scanner can provide higher accuracy and faster speed.

Installation instructions for Piezo Objective Scanner

1)Safety guide

Piezo objective scanner is designed with advanced technology and safety standards. For your safety and the correct use of the product, please pay attention to the following points.

Temperature changes and pressure will charge the piezo driver, and the piezo driver will remain charged for a period after disconnected from the controller, so please be well noted of the following before using:

Do not remove the piezo objective scanner without authorization.
Discharge the piezoelectric objective scanner before installation, which can be achieved by connecting to the controller.
Do not remove the controller during operation.
Before use, please make sure the connection cable is in good condition, the product and the controller are effectively grounded, during the operation please be strictly follow the instruction, do not touch the product after power on (up to 150V voltage) to prevent danger.
To prevent damage caused by improper operation, please pay attention to the following points:
Piezo objective scanner should be used in dust-free, oil-free and lubricant-free environment as far as possible.
As the product adopts flexible structure design, it is recommended that the load should not exceed the carrying capacity of the product, and the torque should not be too large when loading. Do not pry or twist the load surface, so as not to damage the structure.
For long-term use please apply to the recommended voltage (generally 0~120V) when driving.
Do not disassemble the product to avoid damage.
To avoid cable damage, do not stretch or bend the cable connector.
Please use the cable from Coremorrow for the connection between scanner and controller
Do not use extension cable without permission, if you need longer cable, please contact us.

2)Installation and precautions

Before installation, safety check should be carried out first, eg. whether the connection line is damaged or broken, and whether the driving power supply is grounded.

The steps for installing the piezo objective scanner are as follows:

1. Screw and tighten the appropriate objective adapter into the objective scanner with a too.

2. Screw the objective into the objective adapter and tighten it.

3. Fix the installed objective scanner and the microscope connecting end.

During the installation process, it is necessary to handle the piezoelectric objective lens with care so as not to damage the locator or scratch and wear the objective lens.
The load should not exceed the maximum allowable load of the scanner.
Connect the product cable to the corresponding interface of the controller according to the mark near the connector.

The LEMO connection is as the below figure:

Please refer to the following placement method for connection load:
Correct way to apply load

Try not to let the position of the center of gravity far exceed the active platform
When connecting the objective lens, pay attention to the quality of the objective lens, it should not exceed the maximum load allowed by the scanner, and the load should not be too long, to avoid oscillating and damaging the objective scanner.

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