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At a current value of 25.5%, perovskites have reached some of the highest power conversion efficiencies of all single-junction solar cell devices. Researchers, however, are questioning their readiness for the commercial market, citing reasons of the toxicity of the lead-based active layer and instability. Closer examination of the life cycle of perovskite solar cells reveals that there are more areas than just these which should be addressed in order to bring an environmentally friendly and sustainable technology to global use. In this review, we discuss these issues. Life cycle analyses show that high temperature processes, heavy use of organic solvents, and extensive use of certain materials can have high up and downstream consequences in terms of emissions, human and ecotoxicity. We further bring attention to the toxicity of the perovskites themselves, where the most direct analyses suggest that the lead cannot be considered totally safe, despite its small quantity and that replacements such as tin may be more toxic in certain scenarios. As a way to reduce the negative environmental impact, we highlight ways in which researchers have used encapsulation and recycling to extend the life of the entire unit and its components and to prevent lead leakage. We hope this review directs researchers toward new strategies to introduce a clean solar technology to the world.In this work, we introduce polarimetric balanced detection as a new attenuated total reflection (ATR) infrared (IR) sensing scheme, leveraging unequal effective thicknesses achieved with laser light of different polarizations. We combined a monolithic widely tunable Vernier quantum cascade laser (QCL-XT) and a multibounce ATR IR spectroscopy setup for analysis of liquids in a process analytical setting. Polarimetric balanced detection enables simultaneous recording of background and sample spectra, significantly reducing long-term drifts. The root-mean-square noise could be improved by a factor of 10 in a long-term experiment, compared to conventional absorbance measurements obtained via the single-ended optical channel. The sensing performance of the device was further evaluated by on-site measurements of ethanol in water, leading to an improved limit of detection (LOD) achieved with polarimetric balanced detection. Sequential injection analysis was employed for automated injection of samples into a custom-built ATR flow cell mounted above a zinc sulfide multibounce ATR element. The QCL-XT posed to be suitable for mid-IR-based sensing in liquids due to its wide tunability. Polarimetric balanced detection proved to enhance the robustness and long-term stability of the sensing device, along with improving the LOD by a factor of 5. This demonstrates the potential for new polarimetric QCL-based ATR mid-IR sensing schemes for in-field measurements or process monitoring usually prone to a multitude of interferences.A robust, tough, and self-healable elastomer is a promising candidate for substrate in flexible electronic devices, but there is often a trade-off between mechanical properties (robustness and toughness) and self-healing. Here, a poly(dimethylsiloxane) (PDMS) supramolecular elastomer is developed based on metal-coordinated bonds with relatively high activation energy. The strong metal-coordination complexes and their corresponding ionic clusters acting as the cross-linking points strengthen the resultant supramolecular networks, which achieves superior mechanical robustness (2.81 MPa), and their consecutive dynamic rupture and reconstruction efficiently dissipate strain energy during the stretching process, which leads to an impressive fracture toughness (32 MJ/m3). Additionally, the reversible intermolecular interactions (weak hydrogen bonds and strong sacrificial coordination complexes/clusters) can break and re-form upon heating; thus, the elastomer self-heals at a moderate temperature with the highest healing efficiency of 95%. As such, the potential of the as-prepared supramolecular elastomer for a substrate material of flexible electronic devices is discovered.In the face of the global threat from drug-resistant superbugs, there remains an unmet need for simple and accessible diagnostic tools that can perform important antibiotic susceptibility testing against pathogenic bacteria and guide antibiotic treatments outside of centralized clinical laboratories. As a potential solution to this important problem, we report herein the development of a microwell array-based resazurin-aided colorimetric antibiotic susceptibility test (marcAST). this website At the core of marcAST is a ready-to-use microwell array device that is preassembled with custom titers of various antibiotics and splits bacterial samples upon a simple syringe injection step to initiate AST against all antibiotics. We also employ resazurin, which changes from blue to pink in the presence of growing bacteria, to accelerate and enable colorimetric readout in our AST. Even with its simplicity, marcAST can accurately measure the minimum inhibitory concentrations of reference bacterial strains against common antibiotics and categorize the antibiotic susceptibilities of clinically isolated bacteria. With more characterization and refinement, we envision that marcAST can become a potentially useful tool for performing AST without trained personnel, laborious procedures, or bulky instruments, thereby decentralizing this important test for combating drug-resistant superbugs.Silver tungstate (Ag2WO4) shows structural polymorphism with different crystalline phases, namely, orthorhombic, hexagonal, and cubic structures that are commonly known as α, β, and γ, respectively. In this work, these Ag2WO4 polymorphs were selectively and successfully synthesized through a simple precipitation route at ambient temperature. The polymorph-controlled synthesis was conducted by means of the volumetric ratios of the silver nitrate/tungstate sodium dehydrate precursors in solution. The structural and electronic properties of the as-synthesized Ag2WO4 polymorphs were investigated by using a combination of X-ray diffraction and Rietveld refinements, X-ray absorption spectroscopy, X-ray absorption near-edge structure spectroscopy, field-emission scanning electron microscopy images, and photoluminescence. To complement and rationalize the experimental results, first-principles calculations, at the density functional theory level, were carried out, leading to an unprecedented glimpse into the atomic-level properties of the morphology and the exposed surfaces of Ag2WO4 polymorphs.