Wide-Range Linear Iontronic Pressure Sensor with Two-Scale Random Microstructured Film for Underwater Detection.

Area of Science:

• Materials Science
• Sensor Technology
• Nanotechnology

Background:

• Ionic flexible sensors (IFSs) are crucial for accurate pressure acquisition but often suffer from decreasing sensitivity at higher pressures, limiting their linearity and applications.
• Achieving a broad linear range and high sensitivity in IFSs is essential for simplifying signal processing and enabling wider use.

Purpose of the Study:

• To develop an ionic flexible sensor (IFS) with ultra-high linearity and stable sensitivity over a wide pressure range.
• To enhance the performance of IFSs through novel material design and electrode fabrication.

Main Methods:

• Fabrication of a two-scale random microstructure ionic gel film with enhanced porosity and a rough surface.
• Development of multilayer graphene electrodes using a scalable roll-to-roll process for improved ion migration and capacitance.
• Characterization of sensor performance, including linearity, sensitivity, response time, and mechanical stability.

Main Results:

• The developed IFS demonstrated ultra-high linearity (correlation coefficient ~ 0.9931) over a broad pressure range (0-1 MPa).
• Achieved excellent sensitivity (~12.8 kPa⁻¹), fast response (~20 ms) and relaxation (~30 ms) times, and a low detection limit (~2.5 Pa).
• The sensor exhibited outstanding mechanical stability and a wide linear response range.

Conclusions:

• The novel ionic gel film and graphene electrode design effectively overcomes the linearity limitations of traditional IFSs.
• This work provides a viable strategy for creating wide-range linear response sensors with potential applications in soft robotics and underwater monitoring.