Sensitivity-enhanced uncooled infrared detector based on a Lamb wave sensor with polydopamine coating

In this letter, we demonstrate an uncooled, sensitivity-enhanced infrared (IR) detector based on a Lamb wave sensor coated with polydopamine (PDA). The real-time resonant frequency responses of the sensors with and without PDA coating were measured as functions of IR intensity. Compared to the traditional Lamb wave sensor, the PDA-coated Lamb sensor exhibits a highly linear relationship between resonance frequency and IR intensity, and the slope representing the sensitivity of IR detection is nearly one order of magnitude higher. The enhanced sensitivity is mainly attributed to the optical-thermal transition of PDA nanoparticles rather than the modulation of the thermalacoustic effect. This mechanism for achieving highly sensitive uncooled IR detectors holds great promise for application in photo-thermal therapy along with other military and civilian fields. Published under license by AIP Publishing.