Development of a portable holographic lens-free microscope for cells and microorganisms observation
Lens-free microscopy is an emerging field, which represents an alternative to traditional microscopy. The involved technique has the advantage to dissociate resolution from field of view besides being used in compact systems.
In this study, we are developing a portable lens-free holographic microscope, which uses interference patterns from the sample to produce phase and amplitude images with a wide field of view.
For this, multiple images with different sample to sensor distances are captured and used as input information to a digital image processing. Because the images are recorded with no more than a few millimeters distance from the sample, the system has unit magnification, so the observation area is maximized and almost equal to the active area of the imaging device.
The hardware is composed of a compact and portable structure, constructed to perform transmission images using an illumination from an LED with increased coherence.
To make the system user friendly, a software with a graphical user interface was developed especially for automated acquisition control.
The system provides images with almost 30 mm2 and 4 µm of resolution and, because it has flexibility of making amplitude and phase images, it allows observations of different samples, specially biological microstructures as cells and microalgae.
Camila de Paula D'Almeida
University of São Paulo
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