Aluminum Hydroxide Nano- and Microstructures Fabricated Using Scanning Probe Lithography with KOH Ink
Jehyeok Ryu1, Jeong-Sik Jo2, Jin-Hyun Choi1
1Department of Physics, Pukyong National University, Busan 48513, Republic of Korea.
ACS Omega
|March 27, 2023
Summary
This study demonstrates a novel method for fabricating aluminum hydroxide (Al(OH)3) nano- and microstructures using scanning probe lithography (SPL) and KOH ink. The process relies on pH-dependent solidification for precise feature control.
Area of Science:
- Materials Science
- Nanotechnology
- Surface Chemistry
Background:
- Fabricating nano- and microscale features is crucial for advanced materials and devices.
- Existing methods for creating aluminum hydroxide structures can be complex and require specialized equipment.
- Controlling feature size and morphology at the nanoscale presents significant challenges.
Purpose of the Study:
- To develop a novel, efficient, and scalable method for fabricating aluminum hydroxide (Al(OH)3) nano- and microfeatures.
- To investigate the role of pH-dependent solidification in controlling the size and morphology of Al(OH)3 structures.
- To demonstrate the application of dip-pen nanolithography (DPN) and polymer-pen lithography (PPL) for fabricating these features.
Main Methods:
- Utilized scanning probe lithography (SPL) techniques, specifically dip-pen nanolithography (DPN) and polymer-pen lithography (PPL).
- Employed potassium hydroxide (KOH) ink to create aluminum hydroxide (Al(OH)3) on a gold (Au) film deposited on an aluminum (Al) layer.
- Leveraged pH-dependent solidification, controlled by KOH ink volume (hundreds of attoliters), to form Al(OH)3 structures.
Main Results:
- Successfully fabricated Al(OH)3 nano- and microfeatures with minimum feature sizes of approximately 300 nm (sub-micron) and ≥4 μm (micron).
- Demonstrated that the volume and phase (solid/gel vs. liquid) of the KOH ink directly influence the resulting Al(OH)3 feature dimensions.
- Achieved feature fabrication under ambient conditions without the need for a molding process.
Conclusions:
- The proposed pH-dependent solidification process offers a facile and effective route for creating Al(OH)3 structures.
- DPN and PPL are suitable techniques for precise deposition of KOH ink, enabling controlled fabrication of nanoscale features.
- This method provides a simpler alternative to existing techniques for Al(OH)3 fabrication, with potential applications in various fields.
