Non-Lithographic Silicon Micromachining Using Inkjet and Chemical Etching

Area of Science:

• Materials Science
• Microfabrication
• Nanotechnology

Background:

• Traditional silicon patterning methods often require complex lithography and vacuum processes.
• Developing cost-effective, scalable, and versatile patterning techniques is crucial for microfluidics and nanotechnology.

Purpose of the Study:

• To introduce a novel, non-lithographical, and vacuum-free method for patterning silicon using inkjet printing and metal-assisted chemical etching (INKMAC).
• To demonstrate the fabrication of silicon microfluidic channels and cavities with controlled dimensions and aspect ratios.
• To explore the potential of the patterned silicon as a template for creating superhydrophobic surfaces.

Main Methods:

• Inkjet printing of commercial silver ink onto a silicon surface to define catalytic patterns.
• Metal-assisted chemical etching (MaCE) to form silicon nanowires in the printed pattern.
• Potassium hydroxide (KOH) wet etching to remove nanowires and create cavities/channels.

Main Results:

• Successfully patterned silicon using the INKMAC method, creating microfluidic channels (50-100 µm width, 10-40 µm depth) and cavities (30 µm diameter, 60 µm depth).
• Achieved aspect ratios close to one for channels and up to two for cavities.
• Demonstrated the potential for polymer replication to create superhydrophobic surfaces from the patterned silicon.

Conclusions:

• The INKMAC method offers a simple, scalable, and versatile approach for silicon microfabrication.
• This technique enables the creation of functional microfluidic devices and templates for advanced surface engineering.
• INKMAC presents a promising alternative to conventional patterning methods for various scientific and technological applications.