Implementation of a color-capable optofluidic microscope on a RGB CMOS color sensor chip substrate

Abstract

We report the implementation of a color-capable on-chip lensless microscope system, termed color optofluidic microscope (color OFM), and demonstrate imaging of double stained Caenorhabditis elegans with lacZ gene expression at a light intensity about 10 mW/cm(2).

Fig. 1

(a) The schematic plot of gravity driven color OFM. (b) The Bayer pattern for the color filter mask of the CMOS sensor. (c) The color OFM device comparing its size with a 10× microscope objective. (d) The schematic plot for the aperture array and the microscope image of an aligned PDMS channel on top of the aperture array. The scale bar is 20 microns.

Fig. 2

The aperture effect on spectral response of the sensor: the solid lines represent the measured transmission data from a color OFM device; the dash lines are the response from a CMOS sensor without any fabrication process. All the transmission data are normalized at 400 nm.

Fig. 3

Dye concentration measured by the logarithm of relative intensity of two different colors. The illumination light passes through Trypan Blue solutions with two intensities of 6mW/cm² and 4mW/cm².

Fig. 4

Construction of a color OFM image of C. elegans with LacZ expression. (a)–(c) From top to bottom are the images from red, green, blue pixels of a C. elegans with blue Xgal stain and Ponceau stain image, (d) the constructed color OFM image shows the nonspecific Ponceau stain (left arrow) and the LacZ staining of the pharyngeal muscles (right arrow), (e) the conventional 10× microscope image of the same sample. The scale bar is 20 microns.