An energy cell for scavenging light and thermal energies is reported. This energy cell, consisting of a carbon nanotube film (CNF) integrated with a lead zirconate titanate cantilever, is capable of converting light and thermal energies into electricity. This device is based on actuation of CNF upon illumination by light and thermal radiation and generates an electric potential of 10 V. Experiments show that 2.1 μW power can be generated at a light intensity of 0.13 W/cm2, sufficient to operate some low-power microsensors and integrated circuits.

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Usually cell-based assay is performed using titer plates. Because of the large library of chemical compounds, robust and rapid methods are required to find, refine and test a potential drug candidate in an efficient manner. In this article, the drug effects analysis on human breast cancer cells with a droplet microfluidic chip is reported. Each droplet serves as a nanoliter-volume titer plate and contains a human breast cancer cell MDA-MB-231, Cytochalasin D drug solution and cell viability indicator such as Calcein AM, which emits cytoplasmic green fluorescence. The drug effects on each cell are monitored in real time using a fluorescence microscope and by analyzing the fluorescence image of each cell. Clear change of the cell shape and size has been observed after the drug treatment, which is similar to that of conventional petri dish technique, suggesting this approach is a potential viable technical platform for drug effect analysis and for high throughput drug screen and discovery.

Real-time tagless monitoring of cell viability using patch-clamp microchips is reported and validated by using fluorescence imaging techniques for the first time. Specifically, four human breast cancer cell lines (MDA-MB231, MDA-MB231-brain metastatic subline (abbreviated as MB231-BR), MB231-BR over-expressing HER2 gene (MB231-BR-HER2), and MB231-BR-vector control for the HER2 (MB231-BR-vector)) have been used for these studies. Systematic experiments on these cells found that the seal impedance/resistance of cells captured by the micro-pipettes always decreases during the process when the cell loses its viability, and therefore it is a valid indicator of live or dead cells. Systematic experiments also found that the Mega-seal of patch-clamp microchip is sufficient for monitoring cell viability. Given its simplicity of direct electrical measurement of cells without fluorescence labeling, this technology may provide an efficient technical platform to monitor the drug effects on cells, thereby significantly benefiting high throughput drug screening and discovery process.