Mohammad M. N. Esfahani

Lab-on-a-chip workshop activities for secondary school students

The ability to engage and inspire younger generations in novel areas of science is important for bringing new researchers into a burgeoning field, such as lab-on-a-chip. We recently held a lab-on-a-chip workshop for secondary school students, for which we developed a number of hands-on activities that explained various aspects of microfluidic technology, including fabrication (milling and moulding of microfluidic devices, and wax printing of microfluidic paper-based analytical devices, so-called μPADs), flow regimes (gradient formation via diffusive mixing), and applications (tissue analysis and μPADs). Questionnaires completed by the students indicated that they found the workshop both interesting and informative, with all activities proving successful, while providing feedback that could be incorporated into later iterations of the event.

Artificial leaf device for hydrogen generation from immobilised C. reinhardtii microalgae

We developed a fully biomimetic leaf-like device for hydrogen production which allows incorporated fabric-immobilised microalgae culture to be simultaneously hydrated with media and harvested from the produced hydrogen in a continuous flow regime without the need to replace the algal culture. Our leaf device produces hydrogen by direct photolysis of water resulting from redirecting the photosynthetic pathways in immobilised microalgae due to the lack of oxygen. In contrast to the many other reports in the literature on batch photobioreactors producing hydrogen from suspension culture of microalgae, we present the first report where this is done in a continuous manner from a fabric-immobilised microalgae culture. The reported artificial leaf device maximises the sunlight energy utilisation per gram of algae and can be upscaled cheaply and easily to cover large areas. We compared the production of hydrogen from both immobilised and suspended cultures of C. reinhardtii microalgae under sulphur, phosphorus and oxygen deprived conditions. The viability and potential of this approach is clearly demonstrated. Even though this is a first prototype, the hydrogen yield of our artificial leaf device is twenty times higher per gram of algae than in previously the reported batch reactors. Such leaf-like devices could potentially be made from flexible plastic sheets and installed on roofs and other sun-exposed surfaces that are inaccessible by photovoltaic cells. The ability to continuously produce inexpensive hydrogen by positioning inexpensive sheets onto any surface could have an enormous importance in the field of biofuels. The proposed new concept can provide a cleaner and very inexpensive way of bio-hydrogen generation by flexible sheet-like devices.

A Disposable Microfluidic Device with a Screen Printed Electrode for Mimicking Phase II Metabolism

Human metabolism is investigated using several in vitro methods. However, the current methodologies are often expensive, tedious and complicated. Over the last decade, the combination of electrochemistry (EC) with mass spectrometry (MS) has a simpler and a cheaper alternative to mimic the human metabolism. This paper describes the development of a disposable microfluidic device with a screen-printed electrode (SPE) for monitoring phase II GSH reactions. The proposed chip has the potential to be used as a primary screening tool, thus complementing the current in vitro methods.

Plastic Scintillator-Based Microfluidic Devices for Miniaturized Detection of Positron Emission Tomography Radiopharmaceuticals

A miniaturized radio-HPLC detector has been developed comprising a microfluidic device fabricated from plastic scintillator in combination with a silicon photomultiplier light sensor, and tested with samples containing a positron-emitting radionuclide, [18 F]fluoride. This cost-effective, small footprint analytical tool is ideal for incorporation into integrated quality control systems for the testing of positron emission tomography (PET) radiopharmaceuticals to good manufacturing practice (GMP) standards.

The Preparation of Microfluidic Architecture with Monolithic Materials Using a Dual Porous Silica Structure

A microfluidic device (MD) has been developed which features a porous silica (PS) monolithic disk synthesized from tetramethyl orthosilicate, incorporated into the device post‐fabrication and sealed in place with a second PS monolithic layer, synthesized from potassium silicate. This dual porous silica (DPS) structure provides a pathway for sample introduction to the MD and offers an ideal platform for solid phase extraction (SPE) methodologies which can be rapidly and efficiently integrated into a chip‐based format. All silica disk manufacture and functionalization was carried out in batch to provide a readily scalable method of production. Application of this design for processing samples was demonstrated using two alternative nucleic acid purification chemistries, yielding polymerase chain reaction amplifiable DNA extracted from 150 μL of human urine in less than 35 min. It is proposed that this DPS system could be further developed for a diverse range of chip‐based SPE applications, providing an interface facilitating sample delivery and enabling SPE on‐chip. Furthermore, to the authors knowledge it is the first reporting of two different types of PS amalgamated in a single MD.