Multiplexed Chemical Sensing CMOS Imager

Abstract

A miniaturized and multiplexed chemical sensing technology is urgently needed to empower mobile devices and robots for various new applications such as mobile health and Internet of Things. Here, we show that a complementary metal-oxide-semiconductor (CMOS) imager can be turned into a multiplexed colorimetric sensing chip by coating micron-scale sensing spots on the CMOS imager surface. Each sensing spot contains nanocomposites of colorimetric sensing probes and silica nanoparticles that enhance sensing signals by several orders of magnitude. The sensitivity is spot-size-invariant, and high-performance gas sensing can be achieved on sensing spots as small as ∼10 μm. This great scalability combined with millions of pixels of a CMOS imager offers a promising platform for highly integrated chemical sensors. To prove its compatibility with mobile electronics, we have built a smartphone accessory based on this chemical CMOS sensor and demonstrated that personal health management can be achieved through the detection of gaseous biomarkers and pollutants. We anticipate that this new platform will pave the way for the widespread application of chemical sensing in mobile electronics and wearable devices.

A Wearable Bracelet for Simultaneous Monitoring of Transcutaneous Carbon Dioxide and Pulse Rates

“…In this work, we propose a wearable bracelet based on a nanomaterials-modified lensless CMOS imager for simultaneous monitoring of TcCO 2 and PR. The concept of lensless imag-ing, previously introduced in our previous work, [32][33][34] is applied in this wearable bracelet. The edge area of the CMOS imager is coated with colorimetric CO 2 sensing units, modified with silica nanoparticles (SiO 2 NPs), for TcCO 2 sensing.…”

A Multimodal Sensing CMOS Imager Based on Dual‐Focus Imaging

“…[ 14 ] In addition to visual applications, CMOS imagers have been applied as gas sensors by printing microdroplets containing chemically sensitive dyes directly on the pixels. [ 15 ] These works have demonstrated the versatility of the CMOS imager as a sensing platform; however, each work focused on only one sensing modality.…”