• Commentary |

    Mobility is an important charge-transport parameter in organic, inorganic and hybrid semiconductors. We outline some of the common pitfalls of mobility extraction from field-effect transistor (FET) measurements and propose practical recommendations to avoid reporting erroneous mobilities in publications.

    • Hyun Ho Choi
    • , Kilwon Cho
    • , C. Daniel Frisbie
    • , Henning Sirringhaus
    •  & Vitaly Podzorov
  • Commentary |

    Biomaterials engineered with specific bioactive ligands, tunable mechanical properties and complex architecture have emerged as powerful tools to probe cell sensing and response to physical properties of their material surroundings, and ultimately provide designer approaches to control cell function.

    • Linqing Li
    • , Jeroen Eyckmans
    •  & Christopher S. Chen
  • Commentary |

    Specialized imaging methods are now available to measure the quantum properties of materials with high sensitivity and resolution. These techniques are key to the design, synthesis and understanding of materials with exotic functionalities.

    • Kathryn Ann Moler
  • Commentary |

    The properties of semiconducting solids are determined by the imperfections they contain. Established physical phenomena can be converted into practical design principles for optimizing defects and doping in a broad range of technology-enabling materials.

    • Aron Walsh
    •  & Alex Zunger
  • Commentary |

    Concerns about the planet's health call for a careful evaluation of the environmental impact of materials choices. Life-cycle assessment is a tool that can help identify sustainable materials pathways by considering the burdens of materials both during production and as a product.

    • Randolph E. Kirchain Jr
    • , Jeremy R. Gregory
    •  & Elsa A. Olivetti
  • Commentary |

    Membrane materials provide economical means to achieve various separation processes — and their capabilities for processing organic fluids look set to expand significantly.

    • Ryan P. Lively
    •  & David S. Sholl
  • Commentary |

    Physicists have discovered a new topological phase of matter, the Weyl semimetal, whose surface features a non-closed Fermi surface whereas the low-energy quasiparticles in the bulk emerge as Weyl fermions. A brief review of these developments and perspectives on the next steps forward are presented.

    • Shuang Jia
    • , Su-Yang Xu
    •  & M. Zahid Hasan
  • Commentary |

    Topological semimetals and metals have emerged as a new frontier in the field of quantum materials. Novel macroscopic quantum phenomena they exhibit are not only of fundamental interest, but may hold some potential for technological applications.

    • A. A. Burkov
  • Commentary |

    Although exciton–polariton lasers have been experimentally demonstrated in a variety of material systems, robust practical implementations are still challenging. Similarities with atomic Bose–Einstein condensates make the system suitable for chip-based quantum simulators for non-trivial many-body physics.

    • Michael D. Fraser
    • , Sven Höfling
    •  & Yoshihisa Yamamoto
  • Commentary |

    Tactile sensors provide robots with the ability to interact with humans and the environment with great accuracy, yet technical challenges remain for electronic-skin systems to reach human-level performance.

    • Chiara Bartolozzi
    • , Lorenzo Natale
    • , Francesco Nori
    •  & Giorgio Metta
  • Commentary |

    Metallic materials are fundamental to advanced aircraft engines. While perceived as mature, emerging computational, experimental and processing innovations are expanding the scope for discovery and implementation of new metallic materials for future generations of advanced propulsion systems.

    • Tresa M. Pollock
  • Commentary |

    Humankind's aerospace aspirations are placing unprecedented demands on vehicle propulsion systems. Advanced structural ceramics are playing a key role in addressing these challenges.

    • Nitin P. Padture
  • Commentary |

    The successful adoption of metallic additive manufacturing in aviation will require investment in basic scientific understanding of the process, defining of standards and adaptive regulation.

    • Jaime Bonnín Roca
    • , Parth Vaishnav
    • , Erica R. H. Fuchs
    •  & M. Granger Morgan
  • Commentary |

    Long commercialization times, high capital costs and sustained uncertainty deter investment in innovation for advanced materials. With appropriate strategies, technology and market uncertainties can be reduced, and the commercialization of advanced materials accelerated.

    • Elicia Maine
    •  & Purnesh Seegopaul
  • Commentary |

    Nucleic acid memory has a retention time far exceeding electronic memory. As an alternative storage media, DNA surpasses the information density and energy of operation offered by flash memory.

    • Victor Zhirnov
    • , Reza M. Zadegan
    • , Gurtej S. Sandhu
    • , George M. Church
    •  & William L. Hughes
  • Commentary |

    In the last few years, the advent of metal halide perovskite solar cells has revolutionized the prospects of next-generation photovoltaics. As this technology is maturing at an exceptional rate, research on its environmental impact is becoming increasingly relevant.

    • Aslihan Babayigit
    • , Anitha Ethirajan
    • , Marc Muller
    •  & Bert Conings
  • Commentary |

    The Paris agreement on climate change represents an important step in the design of a new global framework for the mitigation of greenhouse gas emissions. Energy efficiency and renewable energy are keys for the success of this ambitious agreement.

    • Dolf Gielen
    • , Francisco Boshell
    •  & Deger Saygin
  • Commentary |

    Understanding and controlling anionic redox processes is pivotal for the design of new Li-ion battery and water-splitting materials.

    • A. Grimaud
    • , W. T. Hong
    • , Y. Shao-Horn
    •  & J.-M. Tarascon
  • Commentary |

    Twenty years ago, the 'phonon-glass, electron-crystal' concept changed thinking in thermoelectric materials research, resulting in new high-performance materials and an increased focus on controlling structure and chemical bonding to minimize irreversible heat transport in crystals.

    • Matt Beekman
    • , Donald T. Morelli
    •  & George S. Nolas
  • Commentary |

    Advances in the control of the shape, bonding direction and valency of DNA-coated nanoparticles allow the synthesis of nanoparticle crystallites of ever increasing complexity.

    • Bert Nickel
    •  & Tim Liedl
  • Commentary |

    Recent research has revealed considerable diversity in the short-range ordering of metallic glass, identifying favoured and unfavoured local atomic configurations coexisting in an inhomogeneous amorphous structure. Tailoring the population of these local motifs may selectively enhance a desired property.

    • Evan Ma
  • Commentary |

    It has long been thought impossible for pure metals to form stable glasses. Recent work supports earlier evidence of glass formation in pure metals, shows the potential for devices based on rapid glass–crystal phase change, and highlights the lack of an adequate theory for fast crystal growth.

    • A. Lindsay Greer
  • Commentary |

    Key materials discoveries have prompted the rise of inorganic light-emitting diodes in the lighting industry. Remaining challenges are being addressed to further extend the impact of this technology in lighting, displays and other applications.

    • Philipp Pust
    • , Peter J. Schmidt
    •  & Wolfgang Schnick
  • Commentary |

    Organic semiconducting molecules and colloidal quantum dots both make for excellent luminescent materials. Compared with the more established solid-state light-emitting technologies, organic LEDs and quantum-dot LEDs are in their infancy, yet they offer unique properties.

    • Sebastian Reineke
  • Commentary |

    To design reliable and safe geological repositories it is critical to understand how the characteristics of spent nuclear fuel evolve with time, and how this affects the storage environment.

    • Rodney C. Ewing
  • Commentary |

    Understanding entropic contributions to common ordering transitions is essential for the design of self-assembling systems with addressable complexity.

    • Daan Frenkel
  • Commentary |

    Two conceptual strategies for encoding information into self-assembling building blocks highlight opportunities and challenges in the realization of programmable colloidal nanostructures.

    • Ludovico Cademartiri
    •  & Kyle J. M. Bishop
  • Commentary |

    The rise of metal halide perovskites as light harvesters has stunned the photovoltaic community. As the efficiency race continues, questions on the control of the performance of perovskite solar cells and on its characterization are being addressed.

    • Michael Grätzel
  • Commentary |

    Collective quantum phenomena such as magnetism, superfluidity and superconductivity have been pre-eminent themes of condensed-matter physics in the past century. Neutron scattering has provided unique insights into the microscopic origin of these phenomena.

    • Steven T. Bramwell
    •  & Bernhard Keimer
  • Commentary |

    From its earliest days, crystallography has been viewed as a means to probe order in matter. J. D. Bernal's work on the structure of water reframed it as a means of examining the extent to which matter can be regarded as orderly.

    • Philip Ball
  • Commentary |

    Neutron science has been a remarkable success story for European research. For this to continue, scientists need to be prepared to forge new networks and technologies.

    • Dimitri N. Argyriou
  • Commentary |

    Over the course of its long history, powder diffraction has provided countless insights into the properties of materials. It will continue to do so in the future, but with an emphasis on elucidating how materials respond to external stimuli.

    • Anthony K. Cheetham
    •  & Andrew L. Goodwin
  • Commentary |

    Materials-based control of stem cell fate is beginning to be rigorously combined with traditional soluble-factor approaches to better understand the cells' behaviour and maximize their potential for therapy.

    • P. C. Dave P. Dingal
    •  & Dennis E. Discher
  • Commentary |

    The Middle East is rich in human and natural resources, but many of its countries need a cultural and scientific transformation to reach worldwide recognition in education, research and economic productivity. Several institutions are making a positive impact, kindling hope for a successful 'science spring'.

    • Ahmed H. Zewail
  • Commentary |

    With its strategic location and firm commitment to investing in research, Luxembourg has ambitious plans to become a significant player in the international research arena.

    • Jens Kreisel
    • , Ludger Wirtz
    •  & Marc Schiltz
  • Commentary |

    The preclinical intersection of molecular imaging and gene- and cell-based therapies will enable more informed and effective clinical translation. We discuss how imaging can monitor cell and gene fate and function in vivo and overcome barriers associated with these therapies.

    • Nigel G. Kooreman
    • , Julia D. Ransohoff
    •  & Joseph C. Wu
  • Commentary |

    Nanoparticle-based imaging plays a crucial role in cancer diagnosis and treatment. Here, we discuss the modalities used for molecular imaging of the tumour microenvironment and image-guided interventions including drug delivery, surgery and ablation therapy.

    • Chun Li
  • Commentary |

    Many materials-based therapeutic systems have reached the clinic or are in clinical trials. Here we describe materials design principles and the construction of delivery vehicles, as well as their adaptation and evaluation for human use.

    • Jeffrey A. Hubbell
    •  & Robert Langer
  • Commentary |

    Cancer nanomedicines approved so far minimize toxicity, but their efficacy is often limited by physiological barriers posed by the tumour microenvironment. Here, we discuss how these barriers can be overcome through innovative nanomedicine design and through creative manipulation of the tumour microenvironment.

    • Vikash P. Chauhan
    •  & Rakesh K. Jain
  • Commentary |

    For the case of water on supported graphene, about 30% of the van der Waals interactions between the water and the substrate are transmitted through the one-atom-thick layer.

    • Chih-Jen Shih
    • , Michael S. Strano
    •  & Daniel Blankschtein
  • Commentary |

    The challenge to link understanding and manipulation at the microscale to functional behaviour at the macroscale defines the frontiers of mesoscale science.

    • Sidney Yip
    •  & Michael P. Short
  • Commentary |

    In spite of substantial progress over the past 35 years, underfunding and lack of evaluation are preventing Greek research and technology from reaching its true potential. A coordinated effort between government, academia and industry could lead to viable solutions to the current crisis.

    • Costas M. Soukoulis
  • Commentary |

    Semiconducting quantum dots have been extensively investigated with the idea of using single spins for quantum computing. Whereas access to single electrons and their spins has become routine, the challenges posed by nuclear spins remain ever present.

    • Hugo Ribeiro
    •  & Guido Burkard
  • Commentary |

    A comparison of the mechanical responses of (bio)polymer networks and shape-memory alloys to cyclic loading reveals strong phenomenological similarities resulting from strain-induced structural changes.

    • Kurt M. Schmoller
    •  & Andreas R. Bausch
  • Commentary |

    Unique opportunities arise from exceptional points that coalesce states of an open system in synthetic photonic media, where delicately balanced complex dielectric functions produce unprecedented optical properties.

    • Xiaobo Yin
    •  & Xiang Zhang
  • Commentary |

    The field of photonic crystals has become one of the most influential and wide-ranging realms of contemporary electromagnetics and optics, with numerous more opportunities on the horizon.

    • Sajeev John
  • Commentary |

    The optimal stimulation of tissue regeneration in bone, cartilage and spinal cord injuries involves a judicious selection of biomaterials with tailored chemical compositions, micro- and nanostructures, porosities and kinetic release properties for the delivery of relevant biologically active molecules.

    • Paul Ducheyne
    • , Robert L. Mauck
    •  & Douglas H. Smith
  • Commentary |

    An evolution from natural to highly engineered materials has drastically changed the way in which athletes train and compete. Thanks to challenging technological problems and unconventional commercialization pathways, universities can make a direct impact on the development of sporting goods.

    • Mike Caine
    • , Kim Blair
    •  & Mike Vasquez