Design of H-Shape Chamber in Thermal Bubble Printer

Area of Science:

• Fluid Dynamics
• Microfluidics
• Inkjet Printing Technology

Background:

• Maximizing ink utilization and increasing printing frequency are critical challenges in thermal bubble inkjet printing.
• Existing thermal bubble inkjet heads face limitations in efficient ink usage and operational speed.

Purpose of the Study:

• To enhance the ink utilization rate and printing frequency of thermal bubble inkjet heads.
• To investigate the effect of a novel H-shape flow-limiting structure on ink dynamics.

Main Methods:

• Integration of a flow restrictor and two narrow channels to form an H-shape flow-limiting structure within the inkjet chamber.
• Analysis of ink flow dynamics, including bubble expansion, reverse flow rate, and nozzle refilling, using high-speed measurements.
• Evaluation of printing frequency and droplet volume generated by the modified inkjet head.

Main Results:

• The H-shape structure reduced the maximum reverse ink flow rate by 25% during bubble expansion.
• The structure increased the maximum ink flow rate by 39% during nozzle refilling after bubble collapse.
• Achieved a printing frequency of 40 kHz with a droplet volume of approximately 13.1 pL.

Conclusions:

• The H-shape flow-limiting structure effectively improves ink utilization and printing frequency in thermal bubble inkjet heads.
• This design offers a valuable reference for advanced applications such as cell printing, 3D printing, and bioprinting.
• The findings contribute to the development of more efficient and higher-performance inkjet printing systems.