Lower grade waste heat recovery near room temperature is limited due to multiple technology challenges including low efficiency, high cost, and scalability. Here, a low‐cost and scalable solution process is reported to fabricate a nanostructured SnSe thin film, and a high thermoelectric performance near room temperature is demonstrated. This transport study reveals strong phonon scattering near the interfaces between SnSe nanosheets that introduces a large thermal boundary resistance and an ultralow thermal conductivity of 0.09 W m−1 K−1. Moreover, it is demonstrated that the SnSe thin film can be readily implemented on flexible plastic substrates and preserve the high thermoelectric performance over 1000 bending cycles. Together, this study demonstrates a low‐cost and scalable approach to achieve high‐performance flexible thin film energy harvesting devices to power electronics and sensors near room temperature.

A total-spectrum-utilizing integrated photovoltaic (PV), thermoelectric (TEG), and thermal energy storage fluid (TES) solar energy converter (PV-TEG-TES) with novel device architecture is proposed, and its performance is modeled to demonstrate its viability and optimize its system-level design. By incorporating a top-layer GaAs PV, ultraviolet and visible light is absorbed and converted directly to electricity, while infrared radiation passes through the PV. This infrared radiation is then captured by the TEG and TES layers to supply additional electricity or to be stored as thermal energy. In addition, the TEG converts to electricity otherwise wasted heat from thermalization of photons within the PV layer, and the TES effectively cools the PV, keeping it within adequate operating temperatures. According to analysis predicting upper bound performance, this PV-TEG-TES device can outperform the electrical conversion efficiency of a single GaAs solar cell module by 1.9 percentage points (from 24.1% for PV alone to 26.0% for the combined device, a relative 7.9% improvement), and can convert and store a total of 79.3% of incident solar energy under a concentration ratio of 673 suns per direct solar spectrum. An analytical framework using a successive overrelaxation technique for solutions to the nonlinearly coupled radiative, thermal, fluid, and electrical phenomena in such a PV-TEG-TES device is also discussed, offering a starting point for practical device parameters.

One of the most daunting challenges facing nations today is controlling the spread of increasingly lethal bacteria. Today, a handful of bacteria can no longer be treated with traditional antibiotics and show antibacterial resistance. In this regard, nanotechnology possesses tremendous potential for the development of novel tools which help prevent and combat the spread of unwanted microorganisms. These tools can provide unique solutions for the challenges of the traditional disinfection methods, such as increased antibacterial activity, cost reduction, biocompatibility and personalized treatment. Despite its great potential, nanotechnology remains in its infancy and continued research efforts are required to achieve its full potential. In this chapter, traditional methods and their associated limitations are reviewed for their efficacy against microbial spread, and potential solutions in nanotechnology are described. A review of the state of the art disinfection techniques using nanotechnology is presented, and promising new areas in the field are discussed.

Analysis of isolated cancer cells in circulation is proven to help determine the success of the cancer treatment and understand the genetic signature of cancer disease. Scarcity of these cells in blood circulation (1–10 CTC in 1ml blood) however, makes the isolation process extremely challenging. Ever improving CTC isolation methods fall into two main categories: 1.Immunomagnetic separation based on antibody binding to tumor specific biomarkers expressed on the cell 2. Physical separation based on the size of the CTCs. Efficiency in cell isolation is still low in these techniques due to the variation in expression level of tumor specific antigens and tumor cell size. Therefore, tumor cell isolation strategies using new CTC biomarkers must be explored. In this study, we investigated the feasibility of using mechanical stiffness difference in order to detect and isolate the circulating tumor cells from the blood cells. AFM nanindentation experiments revealed that cancer cells are significantly softer than the surrounding white blood cells and therefore, stiffness can be used as a biomarker for CTC isolation. In addition, finite element analysis simulations have shown that CTC isolation can be performed at high efficiency using stiffness-based isolation. Therefore, stiffness based isolation has a potential to achieve fast, label-free isolation of CTCs at high efficiency for clinical applications.

No abstract