Flexible Pressure Sensor with Tunable Sensitivity and a Wide Sensing Range, Featuring a Bilayer Porous Structure

Area of Science:

• Materials Science
• Nanotechnology
• Wearable Electronics

Background:

• Flexible piezoresistive pressure sensors are crucial for wearable electronics.
• Porous polymer materials enhance sensing range but face limitations with single-sized pores.
• Achieving both high sensitivity and broad sensing range simultaneously remains a challenge.

Purpose of the Study:

• To develop a flexible pressure sensor with tunable sensitivity and a wide pressure range.
• To overcome the limitations of single-sized pore structures in porous polymer sensors.
• To explore the potential of a bilayer porous structure (BLPS) for improved sensor performance.

Main Methods:

• Fabrication of a PDMS-based flexible pressure sensor utilizing a bilayer porous structure (BLPS).
• Employing clamping compression and a sacrificial template method with spherical sucrose cores.
• Tuning sensitivity by adjusting the bilayer thickness ratio to modify Young's moduli.

Main Results:

• The BLPS sensor demonstrated highly uniform pore sizes, enhancing performance consistency.
• Achieved tunable sensitivity with a maximum of 0.063 kPa⁻¹ in the 0-23.6 kPa range and a broad response up to 654 kPa.
• Exhibited a fast response time of 128 ms and excellent fatigue stability over 10,000 cycles.

Conclusions:

• The developed BLPS flexible pressure sensor offers tunable sensitivity and a wide operating range.
• This sensor design overcomes the trade-off between sensitivity and range in traditional porous sensors.
• Potential applications include facial expression monitoring, joint motion detection, and pressure mapping.