Graphene Oxide and Polymer Humidity Micro-Sensors Prepared by Carbon Beam Writing

Area of Science:

• Materials Science
• Nanotechnology
• Sensor Technology

Background:

• Flexible electronics require advanced materials for sensing applications.
• Graphene oxide (GO) and polyimide (PI) are promising materials for sensor fabrication.
• Direct fabrication methods are needed to simplify sensor production.

Purpose of the Study:

• To develop novel flexible micro-scale humidity sensors using ion beam writing.
• To investigate the structural and compositional changes in GO and PI after ion irradiation.
• To evaluate the sensing performance and stability of the fabricated sensors.

Main Methods:

• Direct fabrication of micro-sensors in GO and PI using ion beam writing with carbon ions (5 MeV).
• Characterization of sensor structure using scanning electron microscopy (SEM).
• Analysis of structural and compositional changes using micro-Raman spectroscopy, XPS, RBS, EDS, and ERDA.

Main Results:

• Successful fabrication of flexible micro-humidity sensors without further modification.
• PI sensor conductivity varied by three orders of magnitude across 5-60% relative humidity (RH).
• GO sensor capacitance varied in the pico-farad range across 5-60% RH, with PI demonstrating long-term stability.

Conclusions:

• Ion micro-beam writing is a viable method for creating flexible micro-sensors.
• The fabricated sensors exhibit high sensitivity and stability over a wide humidity range.
• These sensors hold significant potential for diverse applications in humidity monitoring.