THz Bragg structures fabricated with additive manufacturing.

The advancement of THz science and technology is desirable to facilitate the application of THz technologies in many sectors. Specialized THz photonic elements for these applications require desirable absorption and refractive characteristics in the THz regime. THz photonic elements can be created with additive manufacturing, and specifically 3D printing, forgoing the need for complex fabrication procedures and methodologies.

A velocity program using the Kanade-Lucas-Tomasi feature-tracking algorithm with demonstration for pressure and electroosmosis conditions.

Investigating microfluidic flow profiles is of interest in the microfluidics field for the determination of various characteristics of a lab-on-a-chip system. Microparticle tracking velocimetry uses computational methods upon recording video footage of microfluidic flow to ultimately visualize motion within a microfluidic system across all frames of a video. Current methods are computationally expensive or require extensive instrumentation.

A Paper-Based Colorimetric Aptasensor for the Detection of Gentamicin.

Antibiotics are classes of antimicrobial substances that are administered widely in the field of veterinary science to promote animal health and feed efficiency. Cattle-administered antibiotics hold a risk of passing active residues to milk, during the milking process. This becomes a public health concern as these residues can cause severe allergic reactions to sensitive groups and considerable economic losses to the farmer.

Comparison of nonlinear filtering techniques for photonic systems with blackbody radiation.

This work explores a theoretical solution for noise reduction in photonic systems using blackbody radiators. Traditionally, signal noise can be reduced by increasing the integration time during signal acquisition. However, increasing the integration time during signal acquisition will reduce the acquisition speed of the signal.

Voltage control for microchip capillary electrophoresis analyses.

This paper presents an inexpensive and easy-to-implement voltage sequencer instrument for use in microchip capillary electrophoresis (MCE) actuation. The voltage sequencer instrument takes a 0-5 V input signal from a microcontroller and produces a reciprocally proportional voltage signal with the capability to achieve the voltages required for MCE actuation. The unit developed in this work features four independent voltage channels, measures 105 × 143 × 45 mm (width × length × height), and the cost to assemble is under 60 USD.

Microchip capillary electrophoresis dairy device using fluorescence spectroscopy for detection of ciprofloxacin in milk samples.

Detecting antibiotics in the milk supply chain is crucial to protect humans from allergic reactions, as well as preventing the build-up of antibiotic resistance. The dairy industry has controls in place at processing facilities, but controls on dairy farms are limited to manual devices. Errors in the use of these manual devices can result in severe financial harm to the farms.

Scalable optical annealing of microfluidic droplets via whispering gallery mode geometry and infrared illumination.

This work presents a solution to limitations on scalability in traditional on-chip optofluidic polymerase chain reaction (PCR) methods that are based on infrared annealing and droplet-based microfluidics. The scalability in these PCR optofluidic methods is limited by the optical penetration depth of light in a fluid droplet. Traditionally, such an implementation has minimal absorption when the droplet diameter is scaled well below the optical penetration depth due to the small interaction length.

Characterisation of graphene electrodes for microsystems and microfluidic devices.

Fabrication of microsystems is traditionally achieved with photolithography. However, this fabrication technique can be expensive and non-ideal for integration with microfluidic systems. As such, graphene fabrication is explored as an alternative.

Optofluidic lenses with horizontal-to-vertical aspect ratios in the subunit regime.

Elliptical optofluidic lenses can provide tunable optical parameters in different optical planes. This tunability is achieved through modifications to the aspect ratio (AR). We present an optofluidic lens with a subunit AR.

Photoconductive terahertz generation from textured semiconductor materials.

Photoconductive (PC) terahertz (THz) emitters are often limited by ohmic loss and Joule heating-as these effects can lead to thermal runaway and premature device breakdown. To address this, the proposed work introduces PC THz emitters based on textured InP materials. The enhanced surface recombination and decreased charge-carrier lifetimes of the textured InP materials reduce residual photocurrents, following the picosecond THz waveform generation, and this diminishes Joule heating in the emitters.

Ultrafast all-optical technologies for bidirectional optical wireless communications.

In this Letter, a spherical retro-modulator architecture is introduced for operation as a bidirectional transceiver in passive optical wireless communication links. The architecture uses spherical retroreflection to enable retroreflection with broad directionality (2π steradians), and it uses all-optical beam interaction to enable modulation on ultrafast timescales (120 fs duration). The spherical retro-modulator is investigated from a theoretical standpoint and is fabricated for testing with three glasses, N-BK7, N-LASF9, and S-LAH79.

Nanophotonic implementation of optoelectrowetting for microdroplet actuation.

The development and ultimate operation of a nanocomposite high-aspect-ratio photoinjection (HARP) device is presented in this work. The device makes use of a nanocomposite material as the optically active layer and the device achieves a large optical penetration depth with a high aspect ratio which provides a strong actuation force far away from the point of photoinjection. The nanocomposite material can be continuously illuminated and the position of the microdroplets can, therefore, be controlled to diffraction limited resolution.

Retroreflective imaging system for optical labeling and detection of microorganisms.

A retroreflective imaging system for imaging microscopic targets over macroscopic sampling areas is introduced. Detection of microorganism-bound retroreflector (RR) targets across millimeter-scale samples is implemented according to retroreflection directionality, collimation, and contrast design characteristics. Retroreflection directionality is considered for corner-cube (CC) and spherical geometries.

Ultrafast transient responses of optical wireless communication detectors.

In this work, fundamental ultrafast transient responses are studied for optical wireless communication (OWC) detectors. It is shown that material impulse responses, associated with transient photoconductivity, and geometrical input responses, associated with transient optical power, must be considered in tandem when OWC photodetection is pursued with broad spectral and directional characteristics. An OWC detector, composed of GaAs photoconductive gaps in a corner-cube geometry, is fabricated and analyzed.

On-chip digital microfluidic architectures for enhanced actuation and sensing.

An on-chip system is presented with integrated architectures for digital microfluidic actuation and sensing. Localized actuation is brought about by a digital microfluidic multiplexer layout that overcomes the challenges of multi-microdrop interference, and complete two-dimensional motion is shown for microdrops on a 14 × 14 grid with minimized complexity by way of 14+14 inputs. At the same time, microdrop sensing is demonstrated in a folded-cavity design for enhanced optical intensity probing of internal fluid refractive indices.