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The merit of thermally stable MNiSn (M=Ti, Zr, Hf) half-Heusler phases, as n-type thermoelectric materials, for high-temperature power generation has been examined. Sb doping at the Sn site is shown to increase both the figure of merit, ZT, and the temperature at which ZT is maximized. The benefits of increased alloying at the M and Ni sites, on the thermal conductivity and thermoelectric transport properties, have also been investigated. The thermoelectric figure of merit, ZT∼0.8 at T∼800°C, for select Sb-doped MNiSn alloys was found to meet or exceed the industry benchmark set by SiGe alloys.

We have fabricated and tested a sample probe that can measure resistivity (ρ) and thermopower (α) on either bar or rod shaped samples over a temperature span of 300–1000K. The design allows us to perform measurements both in vacuum as well as in inert atmosphere and hence suitable for any oxygen sensitive bulk samples. The main feature is the spring assisted pressure contacts between the sample and the two silver blocks, on which the electrical leads as well as thermocouples are mounted. This enables us to establish good thermal contacts over the entire temperature range of measurements between the sample and the thermocouples. To measure the thermopower, a slowly varying temperature difference (ΔT) is generated across the sample by using a small heater. The resulting slope of thermo-emf (ΔV) vs temperature difference (ΔT) plot is used to obtain the thermopower at any temperature. Resistivity is measured in sequence by a linear four-probe method at the same temperature. Hence in a single experiment, both resistivity and thermopower can be measured. Test measurements carried out on Ni and W standards yielded an accuracy of about few percent for both ρ and α.

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The increasing demands of environmentally sustainable, affordable, and scalable materials have inspired researchers to explore greener nanosystems of unique properties which can enhance the performance of existing systems. Such nanosystems, extracted from nature, are state-of-art highperformance nanostructures due to intrinsic hierarchical micro/nanoscale architecture and generous interfacial interactions in natural resources. Among several, bio-inspired nanosystems graphene nanosystems have emerged as an essential nano-platform wherein a highly electroactive, scalable, functional, flexible, and adaptable to a living being is a key factor. Preliminary investigation project bio-inspired graphene nanosystems as a multi-functional nanoplatform suitable for electronic devices, energy storage, sensors, and medical sciences application. However, a broad understanding of bio-inspired graphene nanosystems and their projection towards applied application is not well-explored yet. Considering this as a motivation, this mini-review highlights the following; the emergence of bio-inspired graphene nanosystems, over time development to make them more efficient, state-of-art technology, and potential applications, mainly biomedical including biosensors, drug delivery, imaging, and biomedical systems. The outcomes of this review will certainly serve as a guideline to motivate scholars to design and develop novel bio-inspired graphene nanosystems to develop greener, affordable, and scalable next-generation biomedical systems.