Redefining Intelligent Sensing Through Flexible Organic Near-Infrared Photodetectors

Near-infrared (NIR) organic photodetectors (OPDs) are revolutionizing sensing technologies with unparalleled adaptability. Engineered from polymer and small-molecule semiconductors, these devices achieve bending radii under millimeter level and stretchability exceeding 30%, enabling seamless integration with biological surfaces and robotic systems. In addition, their tunable spectral response through molecular design powers transformative medical applications. For example,  smart electronic bandages that can monitor wound pH and humidity in real time have also been developed. Manufacturing advancements such as roll-to-roll printing slash production costs to 20% of conventional methods, supporting mass production at 10,000 units/m²/day.

In a review published in Wearable Electronics, a team of researchers from Hong Kong Baptist University highlighted the recent advancements in flexible OPDs and discussed the opportunities and technical challenges presented.

Corresponding author Chair Professor Furong Zhu, Associate Dean of the Faculty of Science at Hong Kong Baptist University, Director of the Institute of Advanced Materials, and the Research Centre of Excellence for Organic Electronics, notes, “The continuous breakthroughs in advanced flexible NIR OPD technology are accelerating its applications in multiple fields.”

These include the high penetration capability of NIR light can be used for cerebral blood flow monitoring, providing a high-precision data source for neural feedback systems. Meanwhile, OPD response speed can be improved through heterojunction design to meet the technical requirement for use in optical communication.

“The chemical composition of food and other organic materials can be determined by measuring their absorption of NIR light,” shares Zhu. “Visible-blind NIR OPD technology analyzes the NIR spectral fingerprint to enable advanced, traceable fruit quality detection, providing insights into sugar levels, acidity, and water content, while improving cost-effectiveness and portability.”

Contact author: Professor Furong Zhu, Department of Physics, Research Centre of Excellence for Organic Electronics, Institute of Advanced Materials, Hong Kong Baptist University, Kowloon Tong, Hong Kong, China, frzhu@hkbu.edu.hk

Funder: This work was financially supported by the Research Grants Council (GRF12302623, 12304024), and Hong Kong Innovation and Technology Commission (GHP/121/21GD), Hong Kong Special Administrative Region, China.

Conflict of interest: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper

See the article: Z. Wang, Y. Tang, M. Gao, J. Han, F. Zhu, Advanced flexible organic near-infrared photodetectors for sensing applications, Wearable Electronics 2, 124-148, (2025) https://doi.org/10.1016/j.wees.2025.04.002