Ahmet F. Coskun

Learn More
We demonstrate a personalized food allergen testing platform, termed iTube, running on a cellphone that images and automatically analyses colorimetric assays performed in test tubes toward sensitive and specific detection of allergens in food samples. This cost-effective and compact iTube attachment, weighing approximately 40 grams, is mechanically(More)
We demonstrate lensfree holographic microscopy on a chip to achieve approximately 0.6 microm spatial resolution corresponding to a numerical aperture of approximately 0.5 over a large field-of-view of approximately 24 mm2. By using partially coherent illumination from a large aperture (approximately 50 microm), we acquire lower resolution lensfree in-line(More)
We demonstrate an on-chip fluorescent detection platform that can simultaneously image fluorescent micro-objects or labeled cells over an ultra-large field-of-view of 2.5 cm x 3.5 cm without the use of any lenses, thin-film filters and mechanical scanners. Such a wide field-of-view lensless fluorescent imaging modality, despite its limited resolution, might(More)
In general, Costea et al.1 do raise an important point: thorough studies of the effects of preprocessing on downstream analyses (of which clustering and differential abundance testing are two) are sorely needed in the field of large-scale metagenomics studies. This is especially important for TSS normalization, which is still in wide use in the field and(More)
We discuss unique features of lens-free computational imaging tools and report some of their emerging results for wide-field on-chip microscopy, such as the achievement of a numerical aperture (NA) of ∼0.8–0.9 across a field of view (FOV) of more than 20 mm2 or an NA of ∼0.1 across a FOV of ∼18 cm2, which corresponds to an image with more than 1.5(More)
The direct observation of nanoscale objects is a challenging task for optical microscopy because the scattering from an individual nanoparticle is typically weak at optical wavelengths. Electron microscopy therefore remains one of the gold standard visualization methods for nanoparticles, despite its high cost, limited throughput and restricted(More)
This paper focuses on multi-antenna systems that employ both maximal-ratio transmission and receive antenna selection (MRT&RAS) in independent and identically distributed Nakagami-m flat-fading channels with channel estimation errors (CEE) [or feedback quantization errors (FQE)] and feedback delay (FD). Useful statistics of the postprocessing(More)
We demonstrate lensfree on-chip fluorescent imaging of transgenic Caenorhabditis elegans (C. elegans) over an ultra-wide field-of-view (FOV) of e.g., >2-8 cm(2) with a spatial resolution of ∼10 µm. This is the first time that a lensfree on-chip platform has successfully imaged fluorescent C. elegans samples. In our wide-field lensfree imaging platform, the(More)
We demonstrate a cellphone based contact microscopy platform, termed Contact Scope, which can image highly dense or connected samples in transmission mode. Weighing approximately 76 grams, this portable and compact microscope is installed on the existing camera unit of a cellphone using an opto-mechanical add-on, where planar samples of interest are placed(More)
In this paper, multiple-input multiple-output (MIMO) systems employing both transmit and receive antenna selection (TAS/RAS) are examined for independent and identically distributed (i.i.d.) flat Nakagami-m fading channels. Exact bit error rate (BER) expression for binary phase shift keying (BPSK) and binary frequency shift keying (BFSK) modulations are(More)