Microstrip Copper Nanowires Antenna Array for Connected Microwave Liquid Sensors.

Area of Science:

• Electrical Engineering
• Materials Science
• Sensor Technology

Background:

• Microstrip antennas operating at high frequencies (e.g., 25 GHz) offer miniaturization potential for sensor applications.
• The 25 GHz frequency band is relevant for radar and emerging 5G technologies, suggesting readily available components and infrastructure.
• Developing cost-effective and compact liquid sensors is crucial for widespread adoption in various monitoring systems.

Purpose of the Study:

• To develop a lightweight and compact liquid sensor using a modified 25 GHz planar microstrip antenna.
• To investigate the feasibility of using anodic oxidation to enhance the sensing capabilities of the microstrip antenna.
• To demonstrate the sensor's ability to detect the presence and concentration of ethanol in water.

Main Methods:

• Design and fabrication of a 25 GHz planar antenna in microstrip technology.
• Modification of the microstrip copper conductor via controlled anodic oxidation to improve sensing performance.
• Experimental testing to evaluate the sensor's response to varying concentrations of ethanol in water.

Main Results:

• The modified antenna successfully detected the presence and concentration of ethanol in water.
• Achieved a sensitivity of 0.21 kHz/(mg/L) with an average quality factor of 117.
• The sensor was realized in a compact size (18 mm × 19 mm) and in a cost-effective manner.

Conclusions:

• The 25 GHz microstrip antenna, enhanced through anodic oxidation, is a viable and cost-effective solution for compact liquid sensing.
• The sensor demonstrates significant potential for detecting ethanol concentration, suitable for integration into wireless smart sensor networks.
• This approach enables the development of next-generation connected sensors for real-time monitoring applications.