Design And Research Of Laser Induced Forward Transfer Printing Control System

Laser induced forward transfer technology is a kind of laser micromachining technology which has developed rapidly in recent years.It has the characteristics of fast and flexible,high processing accuracy,green and environmental protection,etc.It is widely used in the fields of microelectronic equipment,bio-printing preparation and so on,and has a good development prospect.At present,the market lacks a special control system for laser transfer microprinting,and other laser processing control systems lead to more complicated processing steps and low processing efficiency,which makes it difficult to promote the application of this technology in industrial,microelectronics,biomedical and other fields.Therefore,based on laser-induced forward transfer technology,an inexpensive laser-induced forward transfer printing control system is designed in this paper.The main research contents of this paper are as follows:1.Design of laser induced forward transfer printing test device.Based on the in-depth analysis of the principle of laser induced forward transfer printing,the overall design scheme of the experimental device for laser induced forward transfer printing is proposed.Firstly,the experimental device is modeled in three dimensions,and the entity is built according to the model.Secondly,with Arduino UNO R3 demo board as the control core and PC as the human-computer interaction platform,the hardware design scheme of the laser induced forward transfer printing control system is established.Then the stepping motor,travel switch,laser and other key components are selected,and then according to the configuration of each pin after burning GRBL firmware,the circuit wiring diagram is drawn.Finally,based on Visual Studio C# software platform,a master computer software suitable for laser induced forward transfer printing control system is developed.According to the needs of laser induced forward transfer printing,functional modules such as parameter setting,motion control,bitmap printing,vector printing and status display are developed.2.Research on bitmap processing methods of laser induced forward transfer printing.The master computer software can recognize BMP,JPEG,TIFF and other file formats to meet the processing requirements of various bitmap formats.Firstly,the basic composition of bitmap file,taking BMP format as an example,is introduced emphatically.Secondly,the image preprocessing is described in detail: the color image grayscale processing,the grayscale image binary processing,the binary image inverse color processing,the original image geometric transformation.Then three different processing modes are designed,in which the line-by-line scanning mode is mainly described,including the generation of machining path.In addition,two-way scanning is the main mode,adding to horizontal,vertical and diagonal scanning directions.Furthermore,the black and white pattern mode,that is,the binary image is obtained by the error dithering technology,and the vector mode,that is,the bitmap is converted to vector image by the edge contour extraction technology,are designed.Finally,an interface for assigning parameters in laser-induced forward transfer printing is provided,which mainly includes the Settings of the size and position of the picture,as well as the Settings of the printing power and speed.3.Research on laser induced forward transfer printing vector image processing and processing path optimization.In order to solve the problem that the resolution of bitmap is reduced due to amplification,a vector image processing module is designed,which realizes the process of drawing,extracting,parsing and optimizing the vector image,and finally generates the processing code.Firstly,the basic composition of DXF file is introduced in detail,and the extraction process of DXF file data is analyzed emphatically.Secondly,the drawing area is designed and planned,which is mainly used for the drawing of vector graphics,that is,to complete the drawing of basic graphic elements such as lines,circles and arcs,and to provide the editing functions such as translation,rotation and mirror,and finally to save them in the format of DXF files.Finally,the basic principle of ant colony algorithm and its application in laser processing are introduced,and the optimization of printing path is completed by using ant colony algorithm.The printing efficiency will be effectively improved by reasonably planning the path,which is convenient for its application in laser processing.4.Experimental research on laser induced forward transfer printing.Using 80 °C dried silver slurry as the donor material,the accuracy and practicability of code generation were firstly verified by laser direct writing technology.The focus position was obtained when the focal length was 18 mm,and the silver slurry layer was removed by transverse and longitudinal scanning respectively at the focus position to obtain two lines with the same line width.Secondly,the important factors affecting the process of laser induced forward transfer printing were investigated,and the optimal parameters were obtained as follows: the laser power was 500 m W,the laser frequency was 500 Hz,the scanning speed was 160 mm/min,the film thickness was 3-5 μm after drying,and the receiving spacing was 0.Then the bitmap images are printed,which proves that the density of the line plays a decisive role in the bitmap printing effect.At the same time,the image size can be appropriately improved to obtain a better image effect.Finally,the influence of the number of repetitions on the printing effect of vector images is analyzed,that is,when the number of repetitions is 2-3 times,better results can be obtained.