Abstract Whispering gallery mode (WGM) microtoroid resonators are one of the most sensitive biochemical sensors in existence, capable detecting single molecules. The main barrier for translating these devices out laboratory is that light evanescently coupled into though a tapered optical fiber. This hinders translation as taper fragile, suffers from mechanical vibration, and requires precise positioning. Here, we eliminate need an fiber by coupling toroid via free-space monitoring scattered...

Fluidic lenses allow for varifocal optical elements, but current approaches are limited by the speed at which focal length can be changed. Here we demonstrate use of a tunable acoustic gradient (TAG) index refraction lens as fast element. The power TAG varies continuously, allowing rapid selection and modification effective time scales 1 μs shorter. wavefront curvature applied to incident light is experimentally quantified function time, single-frame imaging demonstrated. Results indicate...

We report a mobile-phone based fluorescent microscope that uses machine learning to rapidly image, detect and quantify <italic>Giardia lamblia</italic> cysts in water samples.

In the past two decades or so, there has been a renaissance of optical microscopy research and development. Much work done in an effort to improve resolution sensitivity microscopes, while at same time introduce new imaging modalities, make existing systems more efficient accessible. this review, we look particular aspects renaissance: computational techniques compact platforms. many cases, these go hand-in-hand because use can simplify demands placed on hardware obtaining desired...

We report the discovery of an entirely new three-dimensional (3D) swimming pattern observed in human and horse sperms. This motion is form 'chiral ribbons', where planar swing sperm head occurs on osculating plane creating some cases a helical ribbon others twisted ribbon. The latter, i.e., trajectory, also defines minimal surface, exhibiting zero mean curvature for all points its surface. These chiral patterns cannot be represented or understood by already known sperms other micro-swimmers....

The nitric oxide radical plays pivotal roles in physiological as well atmospheric contexts. Although the detection of dissolved vivo has been widely explored, highly sensitive (i.e., low part-per-trillion level), selective, and humidity-resistant gaseous air remains challenging. In field, humidity can have dramatic effects on accuracy selectivity gas sensors, confounding data, leading to overestimation concentration. Highly selective NO sensors based laser-induced graphene were recently...

Sizing individual nanoparticles and dispersions of provides invaluable information in applications such as nanomaterial synthesis, air water quality monitoring, virology, medical diagnostics. Several conventional nanoparticle sizing approaches exist; however, there remains a lack high-throughput that are suitable for low-resource field settings, i.e., methods cost-effective, portable, can measure widely varying particle sizes concentrations. Here we fill this gap using an unconventional...

Computational microscopy tools, in particular lensfree on-chip imaging, provide a large field-of-view along with long depth-of-field, which makes it feasible to rapidly analyze volumes of specimen using compact and light-weight imaging architecture. To bring molecular specificity this high-throughput platform, here we demonstrate the use plasmon-resonant metallic nanoparticles automatically recognize different cell types based on their plasmon-enhanced holograms, detected reconstructed over...

Optical tweezers are a noncontact method of 3D positioning applicable to the fields micro- and nanomanipulation assembly, among others. In these applications, ability manipulate particles over relatively long distances at high speed is essential in determining overall process efficiency throughput. order maximize manipulation speeds, it necessary increase trapping laser power, which often accompanied by undesirable heating effects due material absorption. As such, majority previous studies...

Abstract Many clinical procedures and biomedical research workflows rely on microscopy, including diagnosis of cancer, genetic disorders, autoimmune diseases, infections, quantification cell culture. Despite its widespread use, traditional image acquisition review by trained microscopists is often lengthy expensive, limited to large hospitals or laboratories, precluding use in point‐of‐care settings. In contrast, lensless lensfree holographic microscopy (LHM) inexpensive widely deployable...

A beam that resembles a Bessel on two scales is generated using tunable acoustic gradient index of refraction (TAG) lens. The minor scale the TAG-generated nondiffracting and self-healing. major diffracts while still forming pattern due to specific geometry TAG optical theory behind lens outlined, experimental itself presented. rings are explained, compared with both axicon-generated conventionally focused Gaussian beams.

Rapid detection of toxic and hazardous gases at trace concentrations plays a vital role in industrial, battlefield, laboratory scenarios. Of interest are both sensitive as well highly selective sensors. Whispering-gallery mode (WGM) microresonator-based biochemical sensors among the most existence due to their long photon confinement times. One main concern with these devices, however, is selectivity toward specific classes target analytes. Here, we employ frequency locked WGM microtoroid...

Nanostructured optical components, such as nanolenses, direct light at subwavelength scales to enable, among others, high-resolution lithography, miniaturization of photonic circuits, and nanoscopic imaging biostructures. A major challenge in fabricating nanolenses is the appropriate positioning lens with respect sample while simultaneously ensuring it adopts optimal size shape for intended use. One application particular interest enhancement contrast signal-to-noise ratio nanoscale objects,...

Providing means for researchers and citizen scientists in the developing world to perform advanced measurements with nanoscale precision can help accelerate rate of discovery invention as well improve higher education training next generation engineers worldwide. Here, we review some recent progress toward making optical measurement tools more cost-effective, field-portable, accessible a significantly larger group educators. We divide our into two main sections: label-based imaging sensing...

The persistence of the global COVID-19 pandemic caused by SARS-CoV-2 virus has continued to emphasize need for point-of-care (POC) diagnostic tests viral diagnosis. most widely used tests, lateral flow assays in rapid antigen and reverse-transcriptase real-time polymerase chain reaction (RT-PCR), have been instrumental mitigating impact new waves pandemic, but fail provide both sensitive readout patients. Here, we present a portable lens-free imaging system coupled with particle...

The free surface of molten nanofilms is known to undergo spontaneous formation periodic protrusions when exposed a large transverse thermal gradient. Early time measurements the array pitch and growth rate in polymer melts confirm process based on long wavelength thermocapillary instability not electrostatic attraction or acoustic phonon driven as previously believed. We find excellent agreement with theoretical predictions provided nanofilm out-of-plane conductivity several times larger...