Molding and embossing are good ways to produce this microtextured surface, however the accuracy of the mold is one of the most important factors as it represents the quality of the molded product. The use of diamond tools for precision machining has been increasingly used to manufacture high-precision machined parts for advanced industrial applications.

The technique of using diamond tools to fabricate microstructures and micro-grooving can be used for planar machining, which requires the use of ultra-precise motion mechanisms of piezo fast tool positioning platforms and complex control systems to achieve the desired nanometer/micron level of accuracy. The cutting depth is set by the feed mechanism, and the precision of the parts is directly dependent on the precision of the piezo fast tool positioning stage. 

Piezo fast tool positioning platform is a kind of high precision, high speed, high stiffness, high reliability tool positioning equipment, mainly used in high precision cutting, precision machining, semiconductor manufacturing, precision electronics, optoelectronics, precision instruments and other fields. It is driven by piezo ceramics and achieves high precision tool positioning through fast deformation. The control system controls the power supply and signal of the piezo driving mechanism to realize the precise control of the tool position. The piezo fast tool positioning stage can improve the working efficiency and product quality, reduce the error of manual operation, which is one of the important equipment of modern high-tech manufacturing and laboratory.  

CoreMorrow P92 Piezo Tool Positioning Table and E01 Piezo Controller

In addition to the above micro feed using piezo fast tool positioning stage, another method of constant force cutting can be used, which can control the normal cutting force applied to the tool to keep the cutting force constant, for example, nanocutting with atomic force microscope (AFM) mechanism. However, due to the limited travel of the piezo scanner used and the low cantilever stiffness, the process cannot be applied to actual cutting.

However, on the basis of AFM nanocutting technology, combined with diamond tools, a cutting system can be formed for micro-scale machining and large cutting area. Similar to the AFM, the system also has a cantilever beam structure on which a diamond cutter is mounted. The system also uses optical methods to measure the torsion and bending of the cantilever to estimate cutting forces. The system is characterized by its ability to create grooves with constant cutting depth on surfaces with inclined and curved surfaces. 

The picture below shows a micro-cutting system that combines AFM with diamond. The system integrates a non-contact capacitance sensor with a PZT piezo actuator, which works in tandem to maintain a constant normal cutting force. 

Both the cantilever beam and the capacitive sensor are installed on the linear guide rail connected with the piezo actuator. The capacitive sensor can detect the deformation and displacement of the cantilever beam, and the piezo actuator can adjust the position in the z-up with nanometer precision. The system can compensate for some of the geometric errors of the moving system, such as shaft misalignment or errors in the tool path.

The Basic Technical Parameters of CoreMorrow Capacitor Sensor are as follows:

In order to control the cutting normal force, the deformation of the free edge of the cantilever is measured by a capacitance sensor. The feedback control system compensates for any deformation of the cantilever beam and its main task to keep the relative position between the sensor and the measuring plate constant. By controlling the expansion or contraction of the piezo actuator during the cutting process, it interacts with the cantilever. The closed-loop system consists of a function generator, a voltage amplifier (controlling the piezoelectric actuator), a piezo actuator, a capacitive sensor, and a controller (proportional integral PI).

CoreMorrow piezo actuator has a variety of models, diameter is optional from 9mm to 45mm, displacement is optional from 7μm to 260μm, output up to tens of thousands of Newtons, and can be customized according to requirements.

Typical Parameter of Piezo Ceramic Actuator:

CoreMorrow piezo amplifiers has many optional functions, optional analog or digital control, optional keyboard operation, software operation, optional board card type, chassis type. We have both small size and high power models to meet the needs of different applications.

Common AFM systems use piezo scanning tubes that not only compensate for cantilever deformation, but also allow for relative X-Y motion between the tip and the surface to be scanned. However, the maximum measuring area of piezo scanning tube is in the order of hundreds of square microns, which cannot meet the requirements of large processing area.

CoreMorrow Piezo Tube Scanner

The basic parameters of CoreMorrow piezo tube scanner are as follows:

In order to solve the problem of small processing area, the cutting system is installed on the three-axis precision machine tool, the system can be adjusted by the three-axis movement, so as to expand the measuring area, to make micro-groove on the surface of a few square centimeters. 

For more information on micro and nano cutting applications, welcome to contact CoreMorrow by 0451-86268790, info@coremorrow.com