Ag Nanowires to Improve Thermal Comfort in Clothes

Researchers at Stanford University, lead by Prof. Yi Cui have proposed a new idea to improve the thermal insulation of our clothes and even being able to increase their temperature to fit our comfort. About half of the global energy consumption is spent in indoor heating. Most of efforts to reduce this are focused on improving building insulation. However, the Stanford group proposed a different approach targeting at our own clothes. They proved that coating clothing with a mesh of silver nanowires provides better insulation than regular clothes and also can be used to generate its own heat. 

(Concept and picture of the nanowires cloth at the left part. On the right top a glove with a S letter coated with the nanowires that remains colder than the rest of the non-coated glove in the IR camera picture at the bottom right. Image from Nano Letters)

Metals can reflect back the body heat more efficiently than fabrics, but they are hard and clothes require soft materials. For this reason they used metallic nanowires. Since metals conduct electricity, by means of a mini battery, a small current can be passed through the nanowire mesh producing heating by Joule effect. Their results can significantly contribute to change the way we heat our buildings and can be seen at Nano Letters. 

Six Materials That Could Change Our World

Graphene (for multiple applications) and perovskites (for solar cells) are two very exciting materials that have captured the attention of the scientific community and are being intensively investigated. They could significantly change our current technologies and our society. But apart from these two, there are other very interesting materials somewhat less popular. In this link a list of six materials that could change the world has being composed. Among them you will find aerogels, self-healing polymers, stanene, light manipulators and thermoelectrics. 

Regarding the latter class of materials, the company Alphabet Energy has recently fabricated a powerful generator that can be used directly in exhaust pipes. The video above shows all the generator's features and design.

Impedance Spectroscopy for the Measurement of Thermoelectric Properties

We have published this month a new article reporting the potential of impedance spectroscopy as a method to measure thermoelectric properties. Impedance spectroscopy has proved to be a very useful and reliable technique in a lot of fields and powerful equipments are available in the market and in many research centres. We have proved in this new article that impednce can also become very useful in the field of thermoelectrics since it can provide the usually required thermoelectric parameters.

In a first approach, by measuring a thermoelectric element using Ag paint as contacts, all the thermal properties (thermal conductivity, thermal diffusivity and specific heat) can be measured if the Seebeck coefficient is known. Secondly, we describe that by attaching contacts of known thermal conductivity, such as the ceramics in the thermoelectric modules, a complete characterisation can be achieved, i. e., the Seebeck coefficient, the electrical conductivity and the mentioned thermal properties can potentially be extracted.

In addition, new parameters such as thermoelectric capacitance and thermoelectric resistances can be extracted which give information about the physics of the device. All these results are available in our article in the Journal of Applied Physics and in the seminar I gave at Purdue University few months ago which has been recorded and published at the Nanohub website.

Efficiency of Perovskite Solar Cells above 20%

The Korean Research Institute of Chemical Technology (KRICT) has fabricated the first Perovskite Solar Cell with efficiency higher than 20 %. An exact value of 20.1 % has been certified by the NREL and it now appears in the updated efficiency chart. This new efficiency increase situates Perovskites very close to some of the Crystalline Silicon technologies, CdTe and CIGS solar cells.

New Website of the Cardiff Thermoelectric and Photovoltaic Laboratory

I am pleased to announce the launch of the new website of the Cardiff Thermoelectric and Photovoltaic Laboratory. It was released few weeks ago and there you can look at all the members that form the Laboratory, the funded projects we are involved in, our research lines and a detailed section with all our facilities. This is the website address: www.thermoelectric.engineering.cf.ac.uk

Perovskite Solar Cells Moving On

I would like to highlight a recent article by Michael Grätzel published in Nature Materials which shows in my opinion a very nice view of the emergence, development, and problems to be addressed in the field of Perovskite Solar Cells. The article covers all the relevant aspects of this novel technology in a brief and clear way, which results very helpful for those non-familiar with the topic or willing to contribute to it.

Special emphasis is given to the issues rising in the characterisation due to hysteresis effects, and the problems to be addressed in order for the technology to reach the market. In this respect, stability studies seem to be scarce and the high toxicity of Pb compounds has to be overcome by searching new perovskite materials.

Top 10 Emerging Technologies for 2014

The World Economic Forum has published a relation of the the top 10 most promising technologies for 2014. Within the selected breakthroughs are the ones related to wearable electronics, storage of electricity, screenless displays and brain-computer interfaces. All these technologies offer solutions to important problems of our society and hence could make an important impact in the economic market. To see the whole list and a brief summary of their relevance, click here.

The Art of Scientific Publication

ACS publications have compiled a list of 20 references that cover a wide range of issues and aspects related to scientific publications. It deals with the preparation of graphics, the role of corresponding authors, preparation of cover letters, rejection and acceptance and up to the reply to reviewers. It is an excellent guidance, made from the point of view of the own editors and worth looking at it. The link is here.

The Prospects of Graphene Applications

Graphene has acquire an enormous interest in the scientific community due to its outstanding properties and the large range of applications it can be used. In this month's issue of Nature Nanotechnology, seven experts briefly comment their views in the potential and challenges in the realization of graphene-based products in a range of fields such as displays, inks, energy, corrosion, health and life science, biomolecular analysis and aerospace. The article can be read here.

(Graphene transparent screen from Nature journal)

Remarks About Record SnSe Thermoelectric Material

Few months ago, a new article appeared in Physics Today describing some concerns and comments about the outstanding properties of the new SnSe material which has shown impressive thermoelectric properties recently. Advantages and disadvantages regarding practical considerations are also included in the article along with some comments from different recognised researchers and laboratories which offer very interesting and critical points of view.