Open hardware for microfluidics: exploiting Raspberry Pi singleboard computer and camera systems for customisable laboratory instrumentation

The integration of Raspberry Pi miniature computer systems with microfluidics has revolu-tionized the development of low-cost and customizable analytical systems in life science labor-atories. This review explores the applications of Raspberry Pi in microfluidics, with a focus on imaging, including microscopy and automated image capture. By leveraging the low-cost, flexi-bility and accessibility of Raspberry Pi components, high-resolution imaging and analysis have been achieved in direct mammalian and bacterial cellular imaging and a plethora of image based biochemical and molecular assays, from immunoassays, through microbial growth, to nucleic acid methods such as real-time-qPCR. The control of image capture permitted by Raspberry Pi hard-ware can also be combined with onboard image analysis. Open-source hardware offers an op-portunity to develop complex laboratory instrumentation systems at a fraction of the cost of commercial equipment and importantly, offer an opportunity to completely customise to meet the users’ needs. However, these benefits come with a trade-off: challenges remain for those wishing to incorporate open-source hardware equipment in their own work, including requirements for construction and operator skill, need for good documentation and the availability of rapid pro-totyping such as 3D printing plus other components. These advances in open-source hardware have the potential to improve efficiency, accessibility, and cost-effectiveness of microfluidic-based experiments and applications

MEMS based heavy metal detector

Water pollution by toxic heavy metals is one of the most serious environmental hazards to humans’ health. As they are emitted into the water resources and adsorbed by soil, plants, fish and animals and eventually accumulate in human bodies causing a variety of serious diseases. Therefore, there is an urgent need to develop a continuous, rapid, automatic, and on-site heavy metals environmental monitoring system for the online detection of heavy metals pollution at various water resources and industrial waste networks. In this thesis the main objective is to develop a microfluidic platform for heavy metal analyte sensing in which a variety of sensing schemes can be applied. The proposed platform contains microfluidic microchannels for the handling and separation of heavy metal analytes to improve the selectivity, integrated with a sensing device for the optical detection and monitoring of various heavy metal analytes and concentrations. In this context, the design and micro-fabrication of polymer based microchannels were conducted as the microfluidic platform on which the integration of the various optical sensing materials can take place. Afterward a novel design of MEMS based Fourier transform spectrometer is proposed, in which a new scheme for input Gaussian beam splitting into symmetrically two semi Gaussian beam is introduced using V shape mirror. The design is fully integrated and can operate in the Infrared and visible region. The analysis shows that, a minimum resolution of 9nm at a wavelength of 1.45μm and a mechanical displacement of 160μm is achievable. Unlike the traditional Michelson interferometer which returns half of the optical power to the source, this design uses the full optical power to get the interference pattern using movable reflecting mirrors thus enhancing the signal to noise ratio, and allowing the use of differential moving scheme for the mirrors which increase the optical path difference by a factor of four. An analytical model that describes the beams propagation and interference is derived using Fourier optics techniques and verified using Finite Difference Time Domain (FDTD) method. Then, a mechanical model that describes the mirror displacement to produce optical pass difference is derived and verified using finite element method (FEM). Finally, the effect of different design parameters on the interference pattern, interferograme and resolution are also shown

Modular integration and on-chip sensing approaches for tunable fluid control polymer microdevices

228 p.Doktore tesi honetan mikroemariak kontrolatzeko elementuak diseinatu eta garatuko dira, mikrobalbula eta mikrosentsore bat zehazki. Ondoren, gailu horiek batera integratuko dira likido emari kontrolatzaile bat sortzeko asmotan. Helburu nagusia gailuen fabrikazio arkitektura modular bat frogatzea da, non Lab-on-a-Chip prototipoak garatzeko beharrezko fase guztiak harmonizatuz, Cyclic-Olefin-Polymer termoplastikozko mikrogailu merkeak pausu gutxi batzuetan garatuko diren, hauen kalitate industriala bermatuz. Ildo horretan, mikrogailuak prototipotik produkturako trantsizio azkar, erraz, errentagarri eta arriskurik gabeen bidez lortu daitezkeenetz frogatuko da

Development of microcantilever sensors for cell studies

Micro- and nano- electromechanical devices such as microcantilevers have paved the way for a large variety of new possibilities, such as the rapid diagnosis of diseases and a high throughput platform for drug discovery. Conventional cell assay methods rely on the addition of reagents, disrupting the measurement, therefore providing only the endpoint data of the cell growth experiment. In addition, these methods are typically slow to provide results and time and cost consuming. Therefore, microcantilever sensors are a great platform to conduct cell culturing experiments for cell culture, viability, proliferation, and cytotoxicity monitoring, providing advantages such as being able to monitor cell kinetics in real time without requiring external reagents, in addition to being low cost and fast, which conventional cell assay methods are unable to provide. This work aims to develop and test different types of microcantilever biosensors for the detection and monitoring of cell proliferation. This approach will overcome many of the current challenges facing microcantilever biosensors, including but not limited to achieving characteristics such as being low cost, rapid, easy to use, highly sensitive, label-free, multiplexed arrays, etc. Microcantilever sensor platforms utilizing both a single and scanning optical beam detection methods were developed and incorporated aspects such as temperature control, calibration, and readout schemes. Arrays of up to 16 or 32 microcantilever sensors can be simultaneously measured with integrated microfluidic channels. The effectiveness of these cantilever platforms are demonstrated through multiple studies, including examples of growth induced bending of polyimide cantilevers for simple real-time yeast cell measurements and a microcantilever array for rapid, sensitive, and real-time measurement of nanomaterial toxicity on the C3A human liver cell line. In addition, other techniques for microcantilever arrays and microfluidics will be presented along with demonstrations for the ability for stem cell growth monitoring and pathogen detection

Development and application of microtechnologies in the design and fabrication of cell culture biomimetic systems

“Lab-On-a-chip” systems have proved to be a promising tool in the field of biology. Currently, cell culture is performed massively on Petri dishes, which have traditionally been used in cell culture laboratories and tissue engineering. However, having proved to be a widely used tool until now, the scientific community has largely described the lack of correlation between the results obtained in the laboratory and the clinical results. This lack of connection between what has been studied in the laboratories and what has been observed in the clinic has led to the search for more advanced alternative tools that allow results to be obtained closer to reality. Thus, the use of microtechnologies in the field of biomedical engineering, presents itself as the perfect tool as an alternative to obsolete traditional media. Thanks to the low volumes of liquid it presents for its use, it also makes it an essential technology for the testing of drugs, new compounds and materials. By being able to more accurately reproduce the biomimetic environment of cell cultures and tissues, they make this technique fundamental as an intermediate step between basic in vitro laboratory tests and preclinical animal tests, resulting from this way in the best alternative for the reduction of both the use of animal models, as in times and costs. For a biomimetic system to be as such, it also needs another series of complementary devices for its better functioning. Micro-valves, micro pumps, flow sensors, O2 sensors, pH, CO2 are fundamental for the correct functioning andsophistication of biomimetic systems. This complexity, on the other hand, is often not perceived by the user since the miniaturization of all these components makes “Lab-On-a-Chip” systems smaller every day, despite numerous control components that can be incorporated.This thesis presents some examples of different microfluidic devices designed and manufactured through the use of microtechnologies, with all applications, focused on their use in biomimetic systems.<br /

Advances in Optofluidics

Optofluidics a niche research field that integrates optics with microfluidics. It started with elegant demonstrations of the passive interaction of light and liquid media such as liquid waveguides and liquid tunable lenses. Recently, the optofluidics continues the advance in liquid-based optical devices/systems. In addition, it has expanded rapidly into many other fields that involve lightwave (or photon) and liquid media. This Special Issue invites review articles (only review articles) that update the latest progress of the optofluidics in various aspects, such as new functional devices, new integrated systems, new fabrication techniques, new applications, etc. It covers, but is not limited to, topics such as micro-optics in liquid media, optofluidic sensors, integrated micro-optical systems, displays, optofluidics-on-fibers, optofluidic manipulation, energy and environmental applciations, and so on

An Exploration of Paul Bowles\u27 Piano-Solo Pieces

This research paper provides a general overview of the piano-solo literature by the American composer Paul Frederic Bowles (1910-1999). Thanks to recent contributions, this repertoire is now available in recordings and musical scores as it has never been before.;This paper is divided into two sections. The first covers the biography of Paul Bowles and his musical achievements as a composer, along with his research into the folk music of Morocco and his literary writings as a music critic for the journal Modern Music and for The New Herald Tribune. The second part is about Bowles\u27 piano-solo output, divided thematically into pieces with similar forms and structures.;For Bowles\u27 solo piano music, theoretical analysis and a review of existing literature help to reveal style traits; these include his preference for short character pieces, in which Bowles employs neoclassical elements, such as melodies with classical harmonies that display bitonal and pandiatonal tendencies, along with ostinato patterns and Alberti-bass accompaniments. Bowles\u27 music often displays ternary or free structures, with motivic development techniques through which themes or passages are derived from previous motives. Jazz and folk idioms are also an important aspect of Bowles\u27 piano music, particularly in his dancelike pieces, many of which display a Latin-American flavor

An Optofluidic Lens Biochip and an x-ray Readable Blood Pressure Microsensor: Versatile Tools for in vitro and in vivo Diagnostics.

Three different microfabricated devices were presented for use in vivo and in vitro diagnostic biomedical applications: an optofluidic-lens biochip, a hand held digital imaging system and an x-ray readable blood pressure sensor for monitoring restenosis. An optofluidic biochip–termed the ‘Microfluidic-based Oil-Immersion Lens’ (mOIL) biochip were designed, fabricated and test for high-resolution imaging of various biological samples. The biochip consists of an array of high refractive index (n = 1.77) sapphire ball lenses sitting on top of an oil-filled microfluidic network of microchambers. The combination of the high optical quality lenses with the immersion oil results in a numerical aperture (NA) of 1.2 which is comparable to the high NA of oil immersion microscope objectives. The biochip can be used as an add-on-module to a stereoscope to improve the resolution from 10 microns down to 0.7 microns. It also has a scalable field of view (FOV) as the total FOV increases linearly with the number of lenses in the biochip (each lens has ~200 microns FOV). By combining the mOIL biochip with a CMOS sensor, a LED light source in 3D printed housing, a compact (40 grams, 4cmx4cmx4cm) high resolution (~0.4 microns) hand held imaging system was developed. The applicability of this system was demonstrated by counting red and white blood cells and imaging fluorescently labelled cells. In blood smear samples, blood cells, sickle cells, and malaria-infected cells were easily identified. To monitor restenosis, an x-ray readable implantable blood pressure sensor was developed. The sensor is based on the use of an x-ray absorbing liquid contained in a microchamber. The microchamber has a flexible membrane that is exposed to blood pressure. When the membrane deflects, the liquid moves into the microfluidic-gauge. The length of the microfluidic-gauge can be measured and consequently the applied pressure exerted on the diaphragm can be calculated. The prototype sensor has dimensions of 1x0.6x10mm and adequate resolution (19mmHg) to detect restenosis in coronary artery stents from a standard chest x-ray. Further improvements of our prototype will open up the possibility of measuring pressure drop in a coronary artery stent in a non-invasively manner.PhDMacromolecular Science and EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/111384/1/toning_1.pd

Newly-Developed Nanostructured Microcantilever Arrays for Gas-phase and Liquid-phase Sensing

The microcantilever (MC) has become a common transducer for chemical and biological sensing in gas phase and liquid phase during recent years. MC sensors provide superior mass sensitivity by converting weak chemical and biological stimuli into high mechanical response. Moreover, other advantages such as small size, low cost and array format have made MCs more attractive than other comparable sensors. Selectivity in MC sensors can be enhanced by creating a differentially functionalized MC array (MCA) with responsive phases (RPs). A well-designed array should incorporate RPs exhibiting a variety of possible interactions with the analytes, and a specific analyte should induce a distinctive response pattern demonstrated by the array. The first major division of the dissertation research work focused on enhancing selectivity of MC sensor by creating a differentiating MCA. The MCs within the array were nanostructured in a previously developed manner. A self-designed capillary array was set up to chemically functionalize different ligands onto individual MCs in an array for metal ion sensing in liquid phase. Another array was prepared by selectively vapor depositing different organic RPs onto nanostructured MCs and applied to landfill siloxane sensing in gas phase. Both of the arrays demonstrated response diversity to the target analytes. The second major division of the dissertation research work focused on developing a new method to modify MC surfaces with a function nanostructure. Aluminium oxide nanoparticles (AONP) were uniformly dispersed onto MC and a roughened surface with high surface area was achieved as stable sensor platform. Alkoxysilyl compounds were then grafted onto this platform as RPs. For demonstration, a MCA functionalized with three different alkoxysilanes was prepared for volatile organic compound sensing in gas phase. Additionally, another MCA was functionalized with anti-human immunoglobulin G and anti-biotin for bio-sensing in liquid phase. Both of the arrays were prepared with the aforementioned capillary array setup. Selective responses of specific analytes, as well as good sensitivity, were obtained from each type of AONP MCA