DNA is packed in a condensed state in nature to serve numerous functions. The condensation of DNA on a surface typically gives polydisperse structures with no spatial organization. Simmel, Bar-Ziv and colleagues have now shown that by patterning a photo-modifiable biochip with an electron beam, DNA dendrites collapse into one-dimensional fibres 20 nm wide stretching over 70 μm in length. As well as allowing micron-scale DNA patterning, the system is suited to probabilistic problems such as solving a maze and could be integrated with biological circuits to regulate downstream processed linked to DNA condensation. The cover image is a scanning electron microscopy image of DNA condensation propagating through a maze to find the shortest path to the exit.

Letter p1076

IMAGE: GüNTHER PARDATSCHER, TECHNICAL UNIVERSITY OF MUNICH AND DAN BRACHA, WEIZMANN INSTITUTE OF SCIENCE, ISRAEL

COVER DESIGN: BETHANY VUKOMANOVIC

The possibility to position individual atoms offers prospects for writing digital data with the highest imaginable storage density, provided that a platform is found that is both reliable and scalable. Floris Kalff and co-workers have now developed a technique allowing thousands of bits to be encoded in the positions of individual chlorine atoms atop a copper crystal. The cover image is a scanning tunnelling microscope image, approximately 35 nm wide, of the atomic bit pattern.

Letter p926; News & Views p919

IMAGE: SANDER OTTE, TU DELFT

COVER DESIGN: BETHANY VUKOMANOVIC

This month marks the tenth anniversary of Nature Nanotechnology. The cover shows a virtual cabinet displaying illustrations selected from our articles published during the past 10 years.

Editorial p825

CREDIT: Wood for cabinet: Tim Messick / E+ / Getty Images. Illustrations: Lauritsen, J. et al. Nat. Nanotech. 2, 53–58 (2007); Comellas-AragonÈs, M. et al. Nat. Nanotech. 2, 635–639 (2007); Grill, L. et al. Nat. Nanotech. 2, 687–691 (2007); Zhu, J. et al. Nat. Nanotech. 3, 477–481 (2008); Bruns, O. et al. Nat. Nanotech. 4, 193–201 (2009); Röcker, C. et al. Nat. Nanotech. 4, 577–580 (2009); Bhaskaran, C. et al. Nat. Nanotech. 5, 181–185 (2010); Lu, J. et al. Nat. Nanotech. 6, 247–252 (2011); Zhang, H. et al. Nat. Nanotech. 6, 277–281 (2011); Ueno, K. et al. Nat. Nanotech. 6, 408–412 (2011); Villar, G. et al. Nat. Nanotech. 6, 803–808 (2011); Yang Lee, B. et al. Nat. Nanotech. 7, 351–356 (2012); Ge, J. et al. Nat. Nanotech. 7, 428–432 (2012); Natalio, F. et al. Nat. Nanotech. 7, 530–535 (2012); Kostiainen, M. et al. Nat. Nanotech. 8, 52–56 (2013); Liu, N. et al. Nat. Nanotech. 9, 187–192 (2014); Ndieyira, J. et al. Nat. Nanotech. 9, 225–232 (2014); Liu, J. et al. Nat. Nanotech. 9, 285–289 (2014); Lin, J. et al. Nat. Nanotech. 9, 436–442 (2014); Ragazzon, G. et al. Nat. Nanotech. 10, 70–75 (2015); Berger, O. et al. Nat. Nanotech. 10, 353–360 (2015); Atre, A. et al. Nat. Nanotech. 10, 429–436 (2015); Tian, Y. et al. Nat. Nanotech. 10, 637–644 (2015); Sun, J. et al. Nat. Nanotech. 10, 980–985 (2015); Chen, P. et al. Nat. Nanotech. 10, 1077–1083 (2015).

COVER DESIGN: BETHANY VUKOMANOVIC

Nanomechanical devices are of interest for studying fundamental physics in the quantum regime and for mass sensing. Graphene-based resonators exhibit high resonant frequencies, multiple mechanical modes and low mass. Using low-tension graphene drums, Mandar Deshmukh and colleagues modulate the tension-mediated nonlinear coupling between various modes of a drum resonator in a controllable manner — leading to transfer of energy between modes. They demonstrate the ability to amplify the motional amplitude in the resonator, thus making it attractive for a wide variety of applications. The cover image is an artist's impression of the dynamical coupling between two modes of a drum and the energy transfer that occurs as a result of the coupling.

Letter p747

IMAGE: ELLA MARUSHCHENKO

COVER DESIGN: BETHANY VUKOMANOVIC

The neuronal membrane progressively collects postsynaptic potential signals from neighbouring neurons and integrates them until a threshold value is reached, resulting in an action potential being fired. Tomas Tuma, Evangelos Eleftheriou and colleagues have now reproduced this integrate-and-fire functionality by means of a single nanodevice working on a typical timescale of a nanosecond. To this end, they exploit the reversible transition between amorphous and crystalline states of chalcogenide-based phase-change materials. These devices display intrinsically stochastic dynamics, analogous to biological neurons, making them extremely appealing for applications in the field of neuromorphic computation.

Article p693; News & Views p655

IMAGE: XVIVO SCIENTIFIC ANIMATION

COVER DESIGN: BETHANY VUKOMANOVIC

Electronic circuits are typically based on semiconducting materials. However, to find devices with novel uses, alternative silicon-free approaches may be required. Yong Yan, Scott Warren, Patrick Fuller and Bartosz Grzybowski have now fabricated flexible electronic circuits based solely on functionalized metal nanoparticles. Combining nanoparticles with oppositely charged ligands on either side of the device controls the electronic current. By incorporating metal nanoparticles functionalized with organic ligands for sensing environmental changes, chemoelectronic devices were prepared that can sense, process and report on chemical signals such as humidity, gases and metal ions. The cover is an image of a typical device embedded in a flexible polymer.

Letter p603; News & Views p579

IMAGE: SCOTT C. WARREN

COVER DESIGN: BETHANY VUKOMANOVIC

Tools for controlling magnetism at the nanoscale are crucial for the development of new paradigms in optics, electronics and spintronics. E. Albisetti, D. Petti, E. Riedo, R. Bertacco and co-workers have now introduced a new concept, thermally assisted magnetic scanning probe lithography, for creating fully reconfigurable magnetic nanopatterns. A hot nanotip is used to perform a highly localized field cooling in antiferromagnetic/ferromagnetic multilayer films. This method allows to reversibly pattern magnetic nanostructures with controlled spin configuration, without changing the film chemistry and topography. The cover image is an artist’s impression of the excitation and propagation of spin waves in a magnonic conduit patterned with the proposed technique.

Article p545

IMAGE: ELLA MARUSHCHENKO

COVER DESIGN: BETHANY VUKOMANOVIC

Bernal (that is, AB-stacked) bilayer graphene (BLG) has a tunable bandgap under an applied electric field. It could find applications in electronics and optoelectronics, for example, and could potentially be converted into diamane. However, scalable synthesis of high-quality BLG has been a challenge. Rodney Ruoff, James Hone, Luigi Colombo and colleagues have now shown that near-millimetre AB-stacked BLG can be grown by oxygen-activated chemical vapour deposition on copper foil and has a bandgap of more than 100 meV. The cover is an artist’s rendition of a Raman mapping image of BLG labelled with carbon isotopes, which has a hexagonal shape and is surrounded by monolayer graphene. Such Raman mapping images helped elucidate the growth mechanism.

Letter p426

IMAGE: YUFENG HAO

COVER DESIGN: BETHANY VUKOMANOVIC

Water pollution affects millions of people worldwide, yet current methods for purifying waste water are generally costly and resource heavy. Raffaele Mezzenga and Sreenath Bolisetty have now developed inexpensive hybrid membranes based on amyloid fibrils and porous carbon that efficiently remove heavy metal ions and radioactive waste from water. In addition, these amyloid-based membranes can reduce metal ion contaminants into elemental metal nanoparticles and films. The cover image is an artist's impression of the purification of a wastewater stream into pure water and precious gold.

Article p365

IMAGE: ELLA MARUSHCHENKO

COVER DESIGN: BETHANY VUKOMANOVIC

A violation of the so-called Bell inequality represents a strong proof of the ability to create and control quantum states of a pair of quantum bits with no classical analogues. Andrea Morello and co-workers have now demonstrated a violation of Bell’s inequality in a pair of qubits in silicon, encoded in the electron spin and the nuclear spin associated with a single phosphorus donor embedded in a nanoelectronic device. The cover image is an artist’s impression of visual fragments mapped spatially from data directly extracted from the measurement of the quantum state of the phosphorus atom. It expresses the creation of entangled qubits that lie at the heart of quantum computation.

Letter p242; News & Views p216

IMAGE: PAUL THOMAS (UNSW), IN COLLABORATION WITH K. RAXWORTHY (CURTIN UNIV.), A. MORELLO AND J. P. DEHOLLAIN (UNSW)

COVER DESIGN: BETHANY VUKOMANOVIC

Biological ion channels control transport across cell membranes. Creating synthetic analogues of these systems could lead to applications in sensing and drug release, but building artificial channels in a predictable and controllable manner is a considerable challenge. Stefan Howorka and colleagues have now created a biomimetic molecular valve that can control the transport of cargo across a bilayer. The valve is made from seven concatenated DNA strands and can distinguish the transport of small organic molecules that differ by the presence of a positively or negatively charged group. The artist’s impression on the cover shows a channel composed of spiralling DNA duplexes and molecular cargo (blue spheres) being transported through it.

Letter p152

IMAGE: MICHAEL NORTHROP

COVER DESIGN: BETHANY VUKOMANOVIC

Nanoparticles functionalized with photoresponsive molecules assemble into supracrystals on irradiation with UV light and disassemble on irradiation with visible light. These dynamic structures can trap small molecules from the surrounding solution and accelerate chemical reactions in repeated cycles. The artist's impression in the cover shows anthracene dimerization inside the supracrystal structure, with reactants going in and products coming out.

Article p82; News & Views p6

IMAGE: ELLA MARUSHCHENKO

COVER DESIGN: BETHANY VUKOMANOVIC