High-Performance Flexible Capacitive Pressure Sensor Based on a Spiked Nickel/Polyimide Composite Nanofiber Membrane

Area of Science:

• Materials Science
• Nanotechnology
• Sensor Technology

Background:

• Flexible capacitive pressure sensors are crucial for electronic skin, medical monitoring, and human-computer interaction.
• Existing sensors often exhibit poor sensitivity and saturation issues under high pressure.

Purpose of the Study:

• To develop high-sensitivity flexible capacitive pressure sensors capable of operating under high pressure.
• To enhance the performance of pressure sensors for applications in wearable systems.

Main Methods:

• Fabrication of flexible capacitive pressure sensors using electrospun polyimide (PI) nanofiber membranes.
• Incorporation of evenly distributed spiked nickel (Ni) particles into PI nanofiber membranes via electrostatic self-assembly.
• Development of a novel integration method for creating arbitrary sensor arrays.

Main Results:

• The introduction of spiked Ni particles significantly increased sensor sensitivity under high pressure due to microcapacitor formation.
• The sensor prototype demonstrated rapid response/recovery times (30/40 ms) and a wide pressure detection range (1.5 MPa).
• A 4-fold increase in sensitivity (4.04 MPa⁻¹ at 0-1.5 MPa) was achieved compared to pure PI nanofiber membranes, with excellent mechanical stability (1000 cycles).

Conclusions:

• The developed spiked Ni-filled nanofiber membrane sensors overcome limitations of traditional sensors, offering superior performance.
• The sensors show great potential for applications in human motion detection, sleeping posture monitoring, and plantar pressure measurement.
• The novel sensor design and integration method pave the way for advanced wearable systems and electronic skin applications.