Materials Horizons

Communications

All original research published in the journal is in the form of Communication articles. These are exceptionally high quality and innovative reports that are of significant broad appeal to the materials science community at large. The research presented should provide new insight into the topic and demonstrate a new concept or a new way of thinking (a conceptual advance), rather than primarily reporting technological improvements. However, outstanding articles featuring truly breakthrough developments such as record performance of materials alone may also be published in the journal.  

Materials Horizons Communications must include a separate ‘new concepts’ statement. This statement should be a paragraph of no more than 200 words and should address the following questions:

• What new concept has been demonstrated?
• What differentiates this concept from existing research?
• What additional insight does your work and the underlying concept bring to the materials science?

This statement will be seen by editors and reviewers and will help ascertain the significance of the research. The statement should not be a summary of the work reported, as in the article abstract. If the paper is accepted, this statement will also be published. Please note that papers cannot be peer-reviewed without this statement.

Although there is no page limit for a Communication, the recommended length is three printed journal pages. Authors are encouraged to provide a succinct and relevant introduction to the research and to consider the use of the electronic supplementary information for additional material. Please see below for some examples of exemplar 'new concepts' statements.

Reviews

Reviews are typically commissioned by the Materials Horizons editorial board and editorial office, although suggestions from readers for topics and authors of reviews are very welcome and should be directed to the editor. Materials Horizons Reviews must be very high quality, authoritative, state-of-the-art accounts of the selected research field.

Reviews should be timely and provide insights based on existing literature as well as being of general interest to the journal's wide readership. All Reviews undergo a rigorous and full peer review procedure, in the same way as regular research papers.

Authors are encouraged to identify areas in the field where further developments are imminent or of urgent need, and any areas that may be of significance to the community in general. Reviews are typically six to eight printed journal pages in length.

Minireviews

Minireviews are highlights or summaries of research in an emerging area of materials science (typically from the last two to three years). They are not intended to be comprehensive overviews, but rather should highlight recent and important developments and provide insights into the emerging area on which they are focused. Minireviews should set the topic in the context of the relevant literature and may include perspectives of the future development of the field.

Perspectives of the future development of the field are appropriate. The recommended length of a Materials Horizons Minireview is three printed journal pages.

Focus articles

Materials Horizons Focus articles are educational articles that can take the form of either an editorial or review article. They are designed to address topic areas which are often misunderstood or require greater explanation.

Focus articles are invited by the Materials Horizons editorial board and editorial office. Suggestions from readers for topics and authors of Focus articles are welcome and should be directed to the editor.

Comments

Comments and Replies are a medium for the discussion and exchange of scientific opinions between authors and readers concerning material published in Materials Horizons.

For publication, a Comment should present an alternative analysis of and/or new insight into the previously published material. Any Reply should further the discussion presented in the original article and the Comment. Comments and Replies that contain any form of personal attack are not suitable for publication. 

Comments that are acceptable for publication will be forwarded to the authors of the work being discussed, and these authors will be given the opportunity to submit a Reply. The Comment and Reply will both be subject to rigorous peer review in consultation with the journal’s Editorial Board where appropriate. The Comment and Reply will be published together.

Rationally designed meta-implants: a combination of auxetic and conventional meta-biomaterials

New Concepts

In this manuscript, the concept of hybrid meta-biomaterials has been demonstrated to improve implant–bone contact in off-axially loaded ‘meta-implants’ (hip stems). A combination of negative and positive Poisson's ratio structures has been shown to create compression on either side of the meta-implant, decreasing the chance of bone–implant interface failure (Hoffman's criterion), minimizing the chance of wear particles entering the enclosed space and improving implant fixation by mechanically stimulating bone growth. While mechanical meta-materials have been studied for a while now, especially auxetic mechanical metamaterials, special combinations of metamaterials are rarely explored. This study highlights the effectiveness of creating hybrid meta-biomaterials, which can be designed to exhibit specific mechanical properties (such as a hybrid Poisson's ratio). Furthermore, this study covers the complete research trajectory from mechanical-biomaterials to their final hybrid application in ‘meta-implants’. It therefore demonstrates a proof-of-concept of applying rational design and meta-biomaterials to improve implant longevity. The significance of combining specific mechanical metamaterials has been proven, and with the recent advances in additive manufacturing this opens up an interesting field of research.

Bioinspired hierarchical composite design using machine learning: simulation, additive manufacturing, and experiment

New Concepts

We demonstrate a new machine learning-based design approach for hierarchical materials. The new designs created by our machine learning model, which is trained with a database of hundreds of thousands of geometries from finite element analysis, are validated using additive manufacturing and experimentation. Whereas most of the previous work applying machine learning in materials science is solely focused on predicting material properties, we aim to go beyond property prediction to optimize specific properties. This is achieved by further augmenting a convolutional neural network model with our self-learning algorithm; the goal being to learn patterns from sampled top-performing geometries to create even better designs, phasing out inferior designs for superior candidates. The result is a suite of new designs that outperform the training set. Additionally, for the first time in literature, we show that machine learning can be used as an alternative method for coarse-graining – analyzing and designing materials without the use of full microstructural data. The coarse-graining is realized by condensing a collection of building blocks into a single unit cell – significantly reducing the number of parameters needed in our machine learning model. Thus, this new approach accelerates the search for high-performing hierarchical materials by orders of magnitude and is widely applicable to other material systems to optimize a variety of properties.

Unexpected surface interactions between fluorocarbons and hybrid organic inorganic perovskites evidenced by PM-IRRAS and their application towards tuning the surface potential

New Concepts

We pioneer the use of a surface-specific IR spectroscopy technique to probe how molecules deposit on the surface of hybrid organic–inorganic perovskites. With over 20% power conversion efficiencies, the latter have emerged as one of the most promising next-generation photovoltaic materials. Although surface passivation can considerably improve their performance, there is as yet little understanding on how molecules interact with the ionic crystal due to the lack of suitable experimental techniques. We show that PM-IRRAS can be adapted to work on perovskites to provide information on the density and orientation of molecules on the surface as well as the chemical nature of the molecules, in much the same way as IR spectroscopy can be used to identify molecules in solution or in the solid state. Thanks to this technique, we were able to evidence the spontaneous formation of ordered monolayers of even simple fluorocarbons onto the perovskite surface. This surprising result evidences the existence of interactions between fluorine atoms and the hydrophilic surface. We further show that it is possible to harness these interactions to tune the surface potential of the material over a 150 mV range through the formation of a single monolayer.