Related Experiment Video
Updated: Jun 14, 2025
Time-resolved ElectroSpray Ionization Hydrogen-deuterium Exchange Mass Spectrometry for Studying Protein Structure and Dynamics
Published on: April 17, 2017
Investigations of the Laser Ablation Mechanism of PMMA Microchannels Using Single-Pass and Multi-Pass Laser Scans
Xiao Li1,2,3, Rujun Tang1,3, Ding Li1,3
1Zhejiang Provincial Key Laboratory of Laser Processing Robotics, College of Mechanical and Electrical Engineering, Wenzhou University, Wenzhou 325035, China.
Abstract:
CO2 laser machining is a cost effective and time saving solution for fabricating microchannels on polymethylmethacrylate (PMMA). Due to the lack of research on the incubation effect and ablation behavior of PMMA under high-power laser irradiation, predictions of the microchannel profile are limited. In this study, the ablation process and mechanism of a continuous CO2 laser machining process on microchannel production in PMMA in single-pass and multi-pass laser scan modes are investigated. It is found that a higher laser energy density of a single pass causes a lower ablation threshold. The ablated surface can be divided into three regions: the ablation zone, the incubation zone, and the virgin zone. The PMMA ablation process is mainly attributed to the thermal decomposition reactions and the splashing of molten polymer. The depth, width, aspect ratio, volume ablation rate, and mass ablation rate of the channel increase as the laser scanning speed decreases and the number of laser scans increases. The differences in ablation results obtained under the same total laser energy density using different scan modes are attributed to the incubation effect, which is caused by the thermal deposition of laser energy in the polymer. Finally, an optimized simulation model that is used to solve the problem of a channel width greater than spot diameter is proposed. The error percentage between the experimental and simulation results varies from 0.44% to 5.9%.
Insights
This study investigates CO2 laser machining of polymethylmethacrylate (PMMA) microchannels. Optimized laser parameters and an incubation effect model improve microchannel fabrication accuracy.
Area of Science:
- Materials Science
- Laser Physics
- Manufacturing Engineering
Background:
- Polymethylmethacrylate (PMMA) microchannel fabrication using CO2 laser machining is cost-effective but lacks detailed understanding of ablation mechanisms.
- Limited research exists on the incubation effect and ablation behavior of PMMA under high-power laser irradiation, hindering accurate microchannel profile prediction.
Purpose of the Study:
- To investigate the ablation process and mechanism of continuous CO2 laser machining for microchannel production in PMMA.
- To analyze the influence of single-pass and multi-pass laser scan modes on ablation characteristics.
- To develop and validate an optimized simulation model for predicting microchannel profiles.
Main Methods:
- Experimental investigation of CO2 laser machining on PMMA.
- Analysis of ablation zones (ablation, incubation, virgin) and their characteristics.
- Parametric study involving laser energy density, scanning speed, and number of scans.
- Development and validation of a simulation model for microchannel width prediction.
Main Results:
- A higher laser energy density in a single pass leads to a lower ablation threshold.
- PMMA ablation is primarily driven by thermal decomposition and molten polymer splashing.
- Channel dimensions (depth, width, aspect ratio) and ablation rates increase with decreased scanning speed and increased scan passes.
- The incubation effect, caused by thermal energy deposition, explains variations in ablation results between different scan modes.
Conclusions:
- CO2 laser machining parameters significantly influence PMMA microchannel characteristics.
- Understanding the incubation effect is crucial for accurate prediction and control of microchannel geometry.
- The proposed simulation model accurately predicts microchannel width, with errors ranging from 0.44% to 5.9%.
