We present an innovative optical particulate matter sensor. This optical sensor ‘on-a-chip’ combines a visible fibered light source and a custom-made CMOS image sensor chip. By illuminating a single particle in an air channel, we can record the light scattering signature on the photodiode matrix. A piece realized in 3D printing achieves fiber alignment and an efficient stray light protection.
A specific scattering pattern occurs from the interaction of light with a single particle. Unlike traditional optical PM sensors based on a single photodiode detection, we measure a lens-free projection of the scattering signature on the nearby image sensor (1.5mm projection distance). This allows us to count particles and determine their size and refractive index. These parameters are retrieved through image processing and by comparison with a radiometric model that calculates the projection of a Lorenz-Mie’s scattering pattern.
We describe the sensing technique, the architecture and fabrication of this sensor as well as the characterization results, which are in good agreement with our theory-based predictions. In particular, we show that it is possible to differentiate calibrated particulates of different sizes (monodisperse polystyrene-latex spheres). The sensor is sensitive enough to detect single particle and smallest than 1μm.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.