Elastomer thin-film pressure sensor based on embedded photonic tunnel-junction arrays

Area of Science:

• Materials Science and Engineering
• Optoelectronics
• Nanotechnology

Background:

• Development of advanced sensors is crucial for various technological applications.
• Existing pressure sensors often lack flexibility, transparency, or biocompatibility.
• Optical sensing offers potential for high sensitivity and remote monitoring.

Purpose of the Study:

• To propose and demonstrate a novel elastomer thin-film pressure sensor.
• To utilize pressure-sensitive optical signals via vertical photonic tunnel-junction couplers.
• To evaluate the sensor's performance in terms of sensitivity, flexibility, and transparency.

Main Methods:

• Fabrication of a 50 μm thick polydimethylsiloxane (PDMS) thin film.
• Embedding vertical photonic tunnel-junction couplers within the PDMS film.
• Testing the optical response of the device under applied external pressure (up to ~40 kPa).

Main Results:

• A significant differential optical power change of ~140% of incident power was observed.
• The sensor demonstrated robust pressure-sensing capabilities under moderate pressure.
• The fabricated sensor exhibited high flexibility, lightweight properties, optical transparency, and biocompatibility.

Conclusions:

• The proposed approach successfully realizes a flexible, optically transparent thin-film pressure sensor.
• Vertical photonic tunnel-junction couplers enable effective pressure sensing through optical signals.
• This technology holds promise for versatile pressure and touch sensing applications.