Devices such as solar and fuel cells have been studied for many decades and noticeable improvements have been achieved. This paper proposes a Micro Photosynthetic Power Cell (μPSC) as an alternative energy-harvesting device based on photosynthesis of blue-green algae. The effect of important biodesign parameters on the performance of the device, such as no-load performance and voltage-current (V-I) characteristics, were studied. Open-circuit voltage as high as 993 mV was measured while a peak power of 175.37 μW was obtained under an external load of 850 Ω. The proposed μPSC device could produce a power density of 36.23 μW/ cm 2 , voltage density of 80 mV/cm 2 and current density of 93.38 μA /cm 2 under test conditions. INNOVATIONEnergy harvesting from photosynthesis of blue-green algae using microfluidic-based microdevices is presented in this paper. A new fabrication technique has been developed to reduce the thickness of the electrode in order to increase the effi ciency of electron transfer. Effi ciency of photosynthetic conversion to electricity will increase only if the cells are very close to the proton exchange membrane (PEM) as it occurs in microfl uidic devices. Th is energy-harvesting method using photosynthesis and polymer devices is greener than those based on photovoltaics and can eventually substitute for photovoltaic devices.

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Large-scale phenotyping of tip-growing cells such as pollen tubes has hitherto been limited to very crude parameters such as germination percentage and velocity of growth. To enable efficient and high-throughput execution of more sophisticated assays, an experimental platform, the TipChip, was developed based on microfluidic and microelectromechanical systems (MEMS) technology. The device allows positioning of pollen grains or fungal spores at the entrances of serially arranged microchannels equipped with microscopic experimental set-ups. The tip-growing cells (pollen tubes, filamentous yeast or fungal hyphae) may be exposed to chemical gradients, microstructural features, integrated biosensors or directional triggers within the modular microchannels. The device is compatible with Nomarski optics and fluorescence microscopy. Using this platform, we were able to answer several outstanding questions on pollen tube growth. We established that, unlike root hairs and fungal hyphae, pollen tubes do not have a directional memory. Furthermore, pollen tubes were found to be able to elongate in air, raising the question of how and where water is taken up by the cell. The platform opens new avenues for more efficient experimentation and large-scale phenotyping of tip-growing cells under precisely controlled, reproducible conditions.

Minimally invasive surgery has been one of the most significant evolutions in medicine. In this approach, the surgeon inserts specially-designed instruments through a small incision on the patient's skin into the body cavities, abdomen, veins or, arteries and performs the surgery on organs. As a major limitation, surgeons lose their natural tactile perception due to indirect touch on the organs. Since the loss of tactile perception compromises the ability of surgeons in tissue distinction and maneuvers, researchers have proposed different tactile sensors. This review is to provide researchers with a literature map for the state-of-the-art of tactile sensors in minimally invasive surgery, e.g. in robotic, laparoscopic, palpation, biopsy, heart ablation, and valvuloplasty. In this regard, the pertinent literature from the year 2000 on sensing principles, design requirements, and specifications were reviewed in this study. The survey showed that size, range, resolution, variation, electrical passivity, and magnetic-resonance-compatibility were the most critical specification to study for tactile sensors. Based on the results, some of the requirements, e.g., magnetic-resonance-compatibility and electrical passivity are of less generality and more applicationdependent; however, size, resolution, and range specifications differ for various applications and are of utmost importance.