Overview
Mid-infrared (MIR) imaging lies in the molecular fingerprint region, enabling highly selective chemical detection for applications in sensing and imaging. However, conventional systems rely on cryogenically cooled detectors and complex readout circuits, limiting scalability and cost-effectiveness. Our work aims to develop a compact, room-temperature MIR imaging platform based on single-pixel imaging (SPI) using graphene nanomechanical resonators. Leveraging graphene’s low mass and strong photothermal response, absorbed MIR radiation is converted into measurable resonance frequency shifts. This approach enables scalable, low-cost infrared imaging systems with potential impact in portable sensing, environmental monitoring, and medical diagnostics.
Featured Publications:
We have demonstrated high-Q graphene trampoline resonators with 4- and 6-tether designs operating at room temperature. These devices exhibit multimode resonances, record f × Q products (up to 4.1 × 10¹¹ Hz), and broad dynamic ranges (~72 dB). Reduced clamping loss enables enhanced performance compared to conventional drumhead resonators. The platform shows strong potential for ultrasensitive sensing and uncooled infrared detection.
Black Phosphorus NEMS Resonant Infrared (IR) Detector
We reported the first experimental demonstration of two-dimensional (2D) black phosphorus (P) nanoelectromechanical (NEMS) resonators for infrared (IR) detection using vibrating channel transistors (VCTs). Resonant motion is excited and read out electrically, enabled by the high field-effect mobility and efficient conductance modulation of black P. Owing to its narrow direct bandgap (Eg ≈ 0.3 eV), the device exhibits strong IR responsivity through resonance frequency shifts upon absorption, achieving R = −0.31 kHz/µW at 785 nm. Furthermore, direct two-port electrical measurements with a local gate enable sensitive, real-time readout without the need for frequency down-mixing techniques.
References:
- Yousuf SMEH, Wang Y, Rudawski NG, Feng PXL*, “Graphene Trampoline Nanomechanical Resonators with Very High Quality Factors and Broad Dynamic Ranges”, Advanced Functional Materials 35, e11158 (2025). DOI: https://doi.org/10.1002/adfm.202511158.
- Islam A, Lee JS, Feng PXL, “Black Phosphorus NEMS Resonant Infrared (IR) Detector”, Proc. 33rd IEEE Int. Conf. on Micro Electro Mechanical Systems (MEMS 2020), 826-829, Vancouver, Canada, January 18-22 (2020). DOI: https://doi.org/10.1109/MEMS46641.2020.9056366.