Low-Cost and Scalable Flexible Infrared Detectors Based on VO₂(B) Nano-Ink: From Single-Device Sensing to Array...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Vanadium oxide (VOx)-based microbolometers are vital for uncooled infrared (IR) imaging but face limitations like low temperature coefficient of resistance (TCR), inflexibility, and high manufacturing costs.
• These drawbacks hinder the development of wearable IR devices and specialized applications.

Purpose of the Study:

• To create a flexible IR thermal detector using VO2(B) nanosheet ink.
• To overcome the limitations of traditional VOx-based IR detectors for wearable and large-area applications.

Main Methods:

• A facile and scalable drop-casting strategy was employed to prepare flexible IR thermal detectors using VO2(B) nanosheet ink.
• The performance of the detector was characterized by measuring its TCR, responsivity, and specific detectivity at room temperature.

Main Results:

• The flexible IR detector achieved a high TCR of 4.57% K⁻¹ at room temperature.
• The device exhibited a responsivity of 9.84 A/W and a specific detectivity of 3.27 × 10⁸ Jones.
• The sensor demonstrated stable and sensitive performance in respiratory rate monitoring and was integrated into a 5 × 5 flexible printed circuit array for noncontact digital IR imaging.

Conclusions:

• A low-cost, scalable materials-to-device integration strategy for flexible IR thermal sensing was established.
• The developed VO2(B)-based flexible IR detector shows significant potential for next-generation wearable and large-area infrared imaging technologies.