In a significant leap for non-destructive testing (NDT) technology, a research group led by Assistant Professor Kou Li at Chuo University, Japan, has developed a spatially accurate, all-printable fabrication strategy for advanced photo-thermoelectric (PTE) sensor sheets. The work, recently published in npj Flexible Electronics, addresses longstanding challenges in integrating multifunctional image sensors for structural and material monitoring.
While PTE sensors offer omni-directional, ultrabroadband detection ideal for NDT, traditional fabrication methods have struggled with spatial misalignment and inefficiencies due to the need for separate processing steps for each sensor component. This new approach eliminates such limitations by deploying a unified, solution-processable ink-based system.
Key innovations of the study include:
- All-ink constituent preparation: The team formulated liquid inks for each sensor component—carbon nanotube (CNT) absorber channels, electrodes, and dopants—enabling streamlined fabrication via solution processing.
- Mechanically alignable printing: Using a single air-jet dispenser printer, the researchers demonstrated high-yield fabrication without manual spatial alignment, integrating all parts in a single printing workflow.
- Use of high-concentration CNT inks: These inks not only facilitated precise channel printing but also enabled the sensors to achieve ultrabroad photodetection across a wide range of wavelengths, performing on par with existing narrowband devices.
- Versatile device applications: The printable PTE sensors were deployed on diverse substrates and in multiple formats—ranging from high-resolution imagers and wearable gloves to transparent scanning patches—making them adaptable tools for structural health monitoring in varied environmental conditions.
According to the research group, this innovation marks a significant step toward scalable, efficient manufacturing of advanced sensor sheets for real-world applications. The new methodology supports ubiquitous deployment across industries that require robust, flexible, and spatially precise non-destructive inspection solutions.
Reference: https://www.eurekalert.org/news-releases/1083620
