Enhanced thermoelectric properties of poly(3-hexylthiophene) nanofiber networks were achieved, through controlling both charge carrier concentration and charge carrier mobility.

In this study, we investigated the impact of molecular and supramolecular structure of conducting polymers (CPs) on their thermoelectric properties. As a model system, poly­(3-alkylthiophene)­s (P3ATs) with different side-chain lengths were prepared through oxidative chemical polymerization and were recrystallized to a well-ordered lamellar structure, resulting in one-dimensional self-assembled nanofibers (evidenced by transmission electron microscopy, X-ray diffraction, and UV–vis spectroscopic measurements). Thermoelectric characterization was performed at different doping levels (precisely tuned by doping in the redox reaction with Ag+ and Fe3+ cations), and the highly doped samples exhibited the best performance for all studied polymers. By varying the length of the alkyl side chain, the supramolecular structure and consequently the electronic properties were varied. The highest electrical conductivity was measured for poly­(3-butylthiophene), rooted in its densely packed structure. The established structure–property relationships, concerning the monotonous decrease of the electrical conductivity with the alkyl side chain length, highlight the importance of the supramolecular structure (interchain distance in this case). These findings may contribute to the rational design of organic thermoelectric materials.

Abstract.Photogates are probably the most commonly used electronic instruments to aid experiments in the field of mechanics. Although they are offered by many manufacturers, they can be too expensive to be widely used in all classrooms, in multiple experiments or even at a home experimentation. Today all computers have a sound card -an interface for analogue signals. It is possible to make very simple yet highly accurate photogates for cents, while much more sophisticated solutions are also available at a still very low cost. In our review we show several experimentally tested ways of implementing sound card photogates in detail, and we also provide a full-featured, free, open-source photogate software as a much more efficient experimentation tool than the usually used sound recording programs. Further information is provided in a dedicated page, www.noise.physx.u-szeged.hu/edudev.

Arduino is a popular and very useful tool in STEM and physics education. Teacher demonstrations, laboratory and home work of students are supported by an incredibly wide range of application examples for a very low cost. Since the heart of the Arduino board is an industrial microcontroller, it is a good chance to teach the basics of the related rules, standards and engineering-like approach of application that is essential in high quality STEM education. We discuss here the output drive capability often misinterpreted in the Arduino community and we also draw the attention to the importance of developing the right attitude.

Small computer board platforms, such as Arduino, Raspberry Pi, and micro: bit are very common, cheap, and useful tools to teach modern technology, coding, and experimenting in different disciplines at various levels. Due to the huge available information on websites, it is very easy to find a solution for almost any job and problem, therefore one may not be motivated to work out an own version, to study carefully, to understand the principles in-depth and to be creative. This is also one of the reasons why so high proportion of the examples employ technically inadequate methods, misleading concepts. These are rather serious problems concerning high-quality science, technology, engineering and mathematics (STEM) education. Although technology and available tools change rapidly, the basic principles remain the same, therefore education should focus on a better understanding of these. On the other hand, it is very important for the future's engineers, developers, and professionals to follow the correct methods, to be reliable, creative, and open to the more and more common interdisciplinary methodology. In this paper, we demonstrate this approach by investigating exciting interdisciplinary phonocardiography and photoplethysmography experiments and related electronics, data acquisition, and signal processing. In our work, we focus on the understanding and applying the correct methods, provide a detailed analysis of common pitfalls and leave room also for additional work. Students and teachers, lecturers can learn what to consider, pick what they find useful for their projects. It is also important to note, that the principles are valid for much other instrumentation and information processing jobs as well.