Highly Sensitive Capacitive Pressure Sensor Based on MWCNTs/TiO₂/PDMS with a Microhemispherical Array and...

Area of Science:

• Materials Science
• Nanotechnology
• Sensor Technology

Background:

• Humanoid robotics advancements necessitate sophisticated flexible sensors for precise linear range detection.
• Existing sensors often face limitations in sensitivity, stability, and detection range.

Purpose of the Study:

• To develop a highly sensitive and stable capacitive flexible pressure sensor for wide linear range detection.
• To investigate the impact of surface modification and microstructures on sensor performance.

Main Methods:

• Fabrication of a capacitive flexible pressure sensor using a multi-walled carbon nanotubes/titanium dioxide/polydimethylsiloxane (MWCNTs/TiO2/PDMS) composite.
• Creation of a micro-hemispherical structure array on the sensor surface using a templating method.
• Surface functionalization of MWCNTs with varying concentrations of γ-aminopropyltriethoxysilane (APTES) to enhance dispersion and interfacial bonding.

Main Results:

• The sensor exhibits dual-stage sensitivity across a broad linear range of 0-95 kPa.
• Achieved sensitivity values of 1.89 ± 0.49 kPa⁻¹ (0-13 kPa) and 7.08 ± 0.63 kPa⁻¹ (13-95 kPa).
• Demonstrated a rapid response time of 200 milliseconds and stability over 2500 loading cycles.

Conclusions:

• The developed F-MWCNTs/TiO2/PDMS sensor shows significant potential for micro-pressure detection, wearable electronics, and array sensing.
• The synergistic effect of microstructures and surface functionalization enhances overall sensing performance.
• The sensor's adaptability confirmed its viability for practical applications in advanced robotics and electronics.