Flexible Microstructured Capacitive Pressure Sensors Using Laser Engraving and Graphitization from Natural Wood

Area of Science:

• Materials Science
• Nanotechnology
• Sensor Technology

Background:

• Laser engraving is a key method for producing porous graphene.
• Conventional capacitive pressure sensors lack flexibility due to metal electrodes.
• There is a need for flexible, high-performance pressure sensors.

Purpose of the Study:

• To develop a fully flexible capacitive pressure sensor.
• To utilize wood-derived laser-induced graphene (LIG) and thermoplastic polyurethane (TPU).
• To achieve high sensitivity and a wide pressure detection range.

Main Methods:

• Fabrication of flexible LIG/TPU electrodes.
• Creation of microhole and microcone arrays using laser engraving on wood and TPU.
• Integration of LIG/TPU electrodes and a TPU dielectric layer into a capacitive pressure sensor.

Main Results:

• The sensor demonstrated high sensitivity (0.11 kPa⁻¹).
• An ultrawide pressure detection range from 20 Pa to 1.4 MPa was achieved.
• Fast response time (~300 ms) and excellent stability (>4000 cycles) were recorded.

Conclusions:

• The developed sensor offers a promising solution for flexible electronic devices.
• The use of readily available wood-derived materials and consistent flexibility meets device requirements.
• This research contributes significantly to the field of flexible sensing technology.