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Soft actuators with variable signal/color play an important role in the fields of targeted locomotion, artificial phototropism, drug screening, cargo transportation, and interactive sensing. The ability to achieve rapid response, large curvature, wide bending angle, and full-color display continues to be an unresolved challenge for artificial actuating materials. Inspired by the angle-dependent structural color of broad-tailed hummingbird and the Janus wettability of the lotus leaf, a Janus photonic soft actuator (JPSA) was fabricated by integrating an underwater super-oleophilic copper micro-nano array and oil-phobic inverse opal through a Laplace channel. The JPSA exhibits unidirectional permeability to underwater oil droplets. Attractively, with the combination of a swellable super-oleophilic surface and photonic crystals, JPSAs were endowed with oil-controlled reversible bending behavior with self-reporting angle-dependent color indication. We described for the first time the directional actuating mechanism induced by underwater oil unidirectional penetration and revealed the corresponding actuating kinetics and the inner-stress distribution/transfer by using structural color. As an extension of such theory, a rapid responsive JPSA with a wide bending angle and full-color self-reporting is further fabricated. This work provides an efficient strategy for oil directional transportation and separation in aqueous media and inspires the fabrication of a soft actuator/sensor with structural color self-reporting.

Magnetic photonic crystal microspheres (MPCMs), featuring the optical performances of photonic crystals (PCs) and magnetic properties of magnetic materials, have attracted increasing interest in biomedical separation and detection, micro-/nano-motors, magnetic displays, and so forth. Herein, we present a robust strategy for the fabrication of new generation MPCMs with angle-independent structural color and extraordinary mechanical stability, by chemically growing an inorganic PC shell onto a strongly magnetic micro inner core. The magnetic micro inner core introduces strong magnetism, allowing the assembly and motion of the MPCMs for magnetoresponsive photonic micromotors. Furthermore, by virtue of the unique pyroelectric and photoelectric effects of a ZnO layer compositing a PC shell, the MPCMs can be used to construct a multifunctional microsensor with quadruple sensing capabilities, including ultraviolet light, heating, infrared light, and an alternating magnetic field. Such a microsensor is further integrated with a Bluetooth transmitter to construct a wireless sensing microdevice, achieving the remote transmission of the stimulus to a mobile device. This work not only provides a novel strategy for fabricating robust, magnetic photonic microspheres but also opens a new avenue for their use as magnetoresponsive photonic micromotors and multifunctional sensing platforms.

Flexible multifunctional fibers have received much attention owing to their wide applications in biomedicine, smart wearable materials, tissue engineering, and sensors. However, the preparation of such flexible fibers with adaptability, multiple functions, and high performances has been a great challenge so far. In this paper, a new type of shape memory photonic crystal fibers (SMPFs) with optical and electrical functions is reported by coaxially growing Al2O3/ZnO photonic shells onto the polyester fiber surface. The resultant SMPFs exhibit tunable structural colors, anisotropic optical reflection property, and excellent mechanical robustness. Particularly, these SMPFs exhibit unique shape memory capability, which is otherwise difficult to achieve in those previous photonic fibers. Benefiting from the photonic band gap and the transparent inner core, these SMPFs show a distinct ability in guiding light into deep tissues along a special channel, enabling their application as a shape memory optical waveguide. In addition, the pyroelectric effect of ZnO allows their uses as a shape memory temperature sensor for dynamically monitoring mouth respiration, nose breathing, and infrared light in real time. This investigation provides a general platform for flexible multifunctional fibers, which is promising in deep tissue phototherapy, wearable electronics, and intelligent robotics.

The integration of novel structures into colloidal crystals provides the possibility of constructing stimuli-responsive photonic materials. However, in most opal and inverse opal structures, replacing the interior air with an infiltrated liquid will cause partial refractive index matching, resulting in the reduction or even disappearance of the photonic band gap. Herein, inspired by the lotus seedpod, an innovative particle-nested double-inverse opal film with fast and reversible structural color switching (≈1 s) is first fabricated by introducing polystyrene (PS) spheres into an inverted opal backbone. Importantly, refractive index matching can be effectively avoided due to the existence of internal PS spheres, and optical switching from diffusive to photonic behavior is achieved by a liquid with low surface tension for the response. Furthermore, a reversible ethanol stimuli-response bilayer double-inverse opal film with multistate switching for information encryption is proposed by combining optical scattering and diffraction. The scattered light from the top layer caused by the randomly distributed and weakly scattering PS spheres within the pores makes the pattern at the bottom invisible. Simultaneously, the display and discoloration of the pattern can be realized instantaneously by ethanol response. Thus, this new preparation strategy exhibits great potential in the security fields.

Biological skin systems can perceive various external stimuli through ion transduction. Especially, the skin of some advanced organisms such as cephalopods can further promptly change body color by manipulating photonic nanostructures. However, the current skin-inspired soft iontronics lack the rapid full-color switching ability to respond to multiple stimuli including tension, pressure, and temperature. Here, an intelligent chromotropic iontronics with these fascinating functions is developed by constructing a biomimetic ultrastructure with anisotropic electrostatic repulsion. This skin-like chromotropic iontronics can synchronously realize electrical response and optical visualization to mechanical strain and tactile sensation by adjusting the ultrastructure in cooperation with ionic mechanotransduction. Notably, it can perform instantaneous geometric changes to thermal stimuli viaan anisotropic electrostatic repulsion interior. Such a capability allows bionic skin to transduce temperature or infrared light into ionic signals and color changes in real time. The design of anisotropic photonic nanostructures expands the intelligent application for soft iontronics at higher levels, providing a concise, multifunctional, interactive sensing platform that dynamically displays stimuli information on its body.

Uniparental embryos derived from only the mother (gynogenetic [GG]) or the father (androgenetic [AG]) are unique models for studying genomic imprinting and parental contributions to embryonic development. Human parthenogenetic embryos can be obtained following artificial activation of unfertilized oocytes, but the production of AG embryos by injection of two sperm into one denucleated oocyte leads to an extra centriole, resulting in multipolar spindles, abnormal cell division, and developmental defects. Here, we improved androgenote production by transferring the male pronucleus from one zygote into another haploid androgenote to prevent extra centrioles and successfully generated human diploid AG embryos capable of developing into blastocysts with an identifiable inner cell mass (ICM) and trophectoderm (TE). The GG embryos were also generated. The zygotic genome was successfully activated in both the AG and GG embryos. DNA methylome analysis showed that the GG blastocysts partially retain the oocyte transcription-dependent methylation pattern, whereas the AG blastocyst methylome showed more extensive demethylation. The methylation states of most known imprinted differentially methylated regions (DMRs) were recapitulated in the AG and GG blastocysts. Novel candidate imprinted DMRs were also identified. The production of uniparental human embryos followed by transcriptome and methylome analysis is valuable for identifying parental contributions and epigenome memory transitions during early human development.

Although the forward diffraction of the three-dimensional (3D) photonic crystal is easily applied to a photoswitch, backward diffraction rainbows are rarely reported. The first rotational photoswitch based on a bilayer 3D photonic crystal with backward diffractions similar to those of two-dimensional photonic crystals was fabricated by vertically combining different thicknesses of nanoparticle templates. When rotating the bilayer photonic crystal, the opening or closing of the rotational photoswitch shows periodic reproducibility values of 30 and 60°. Different periods are regulated by the thickness and scattering effect of the top layer. Moreover, invisible patterns can be encoded and erased by changing the wettability via pH. Because of the decreasing of the refractive index differentials, it will be revealed rapidly when immersed in water. The revealed pattern can be periodically turned on and off by rotating the bilayer photonic crystal. It has great application prospects in optical prism, warning board, anti-counterfeiting, steganography, watermarking, and complex information coding.

Utilizing photonic crystals to fabricate information encryption materials has attracted widespread interest due to their tunable optical properties and responsiveness to external stimuli. In most of the previously reported systems, the information is hidden at a specific angle and the angle-dependent invisibility is a limitation. Meanwhile, poor structural stability is still a key issue that needs to be solved for potential applications. In this paper, a bilayer heterostructure photonic crystal containing ordered hollow silica inverse opal arrays, amorphous silica opal arrays, and poly(vinyl alcohol) (adhesive) is successfully constructed. It makes the information highly invisible at any angle and also achieves information encryption. With this strategy, the information can be hidden by the noniridescent structural color derived from the strong scattering effect of light from the top layer of amorphous silica sphere arrays. After wiping with ethanol or a refractive-index-matching solvent, the scattering effect vanishes and the amorphous silica sphere arrays become transparent. The reflected light of the bottom layer caused by the increasing refractive index contrast between the inside and outside of the hollow silica spheres could rapidly reveal the hidden information. The bilayer photonic crystal exhibits robust structural stability, and the hiding/revealing process is completely reversible, which shows great potential applications in steganography and information encryption.

Multicolored photonic crystal carbon fiber (CF) yarns and fabrics with mechanical robustness in a full spectrum are reported. By facilely controlling the thickness of the periodic layer, a series of photonic CF yarns and fabrics with vivid structural colors ranging from purple, green, yellow, orange, to red are obtained. Interestingly, the prepared multicolored CF yarns show anisotropic optical reflection properties because of their unique axisymmetric geometry, while the plain-woven fabrics exhibit vivid colors even under ambient scattering light. Most importantly, they can withstand cyclical mechanical rubbing, laundering, and accelerated light aging, indicating great potential for practical uses. Finally, considering such impressive characteristics as well as reflection in the visible and near-infrared regions, the above photonic crystal microstructure is further used as a new material for the application of outdoor reflective cooling of the textile surface, demonstrating a superior temperature reduction up to ∼12 °C with respect to the control sample.

Flocculants are crucial agents in wastewater treatment because they can remove oppositely charged impurities effectively and swiftly. However, flocculation also inevitably causes secondary contamination due to the residual properties, nonreusability, and nondegradability of traditional flocculant molecules. Herein, an ecofriendly starch-based flocculant, i.e., 2,4-bis(dimethylamino)-[1,3,5]-triazine-6-starch, was synthesized via a preactivation-etherification strategy. The large molecular weight property of the flocculant produced by this method enhances the intermolecular hydrophobic association, achieving complete phase separation of all flocculant molecules from water and residue-free flocculation for the first time. Importantly, a large molecular weight tertiary amine starch-based flocculant (LMTS) exhibits a remarkable flocculation capacity of over 1800 mg·g–1for dye wastewater, which is significantly higher than that of traditional polyacrylamide and polyaluminum chloride flocculants. Furthermore, the LMTS flocculant could be recycled by pH adjustment, and its structural stability ensured sustained reusability. This high-performance residue-free biomass-based flocculant offers a green advance for wastewater treatment.

Photonic crystal-based ethanol concentration indicators with rapid response and brilliant structural color output definitely take a place in colorimetric sensors. Here, based on the H-bond-regulated swelling of acrylate shape memory polymers (SMPs) and the solvent-induced structural color change of the double inverse opal photonic crystals (DIOPCs), new-type photonic crystals (PCs) colorimetric indicators were constructed, exhibiting a span of maximum reflection wavelength (λmax) up to ∼166 nm in response to alcohols with concentrations from 0 to 100 vol %. DIOPC indicators (DIOPCIs) show a rapid response to alcohols (<1.5 s) and output different structural colors (covering from blue to red). The colorimetric sensing mechanism includes the solvent-triggered recovery of the inverse opal skeleton, the cosolvency effect and H-bonds induced swelling/shrinkage of the polymer, the phase separation between polystyrene (PS) microsphere and polymer skeleton, and the light diffraction of DIOPCs. While ensuring a larger λmaxspan by regulating the H-bond interactions in polymer chains through acrylamide (AAm), AAm-modified DIOPCIs are sensitive to some specific ethanol concentrations. The real-time sensing of ethanol concentration during fermentation verified the practicability of DIOPCIs, thus establishing a visual model between structural color and corresponding fermentation kinetics. We envisage that the DIOPCIs will contribute to the intelligentization of the alcoholic fermentation and distillation industry.

Compared with traditional paper, water rewritable photonic crystal (PC) paper is an environmentally friendly and low resource-consuming material for information storage. Although, recently reported PC papers have high-quality structure color showing promising prospect, the paper size, that is within several centimeters, still limits turning it from potential to reality. Here, we present a new water rewritable PC film as large as the A4 size (210 × 300 mm2) with a high-quality structure color. The material is prepared by thermal assisted self-assembly on the air–liquid interface. To fix such a large-area self-assembled PC film, we partially deform and coalesce the self-assembled nanoparticles, which have low glass transition temperature. This process causes the film to be transparent and structural colorless but still keeps the inner 3D-ordered structure. Then, utilizing the hydrophilic nature of the assembled block, the film can be switched to a structural color state by touching water. Diverse brilliant structural colors appear with different assembled particle (poly(butyl methacrylate-co-methylmethacrylate-co-butyl acrylate-co-diacetone acrylamide) named as PBMBD) sizes. The transparency–structural color transition can be performed multiple times reversibly in all or specific regions of the film. It provides a new solution for future applications of rewriteable PC paper.

Artificial electronic skin (e-skin) that imitates the complex functions of human skin is able to transduce external stimuli into electronic signals. However, it remains challenging to fabricate e-skin sensing materials with extreme stretchability, self-healing, mechanical compliance, extreme temperature tolerance, and an ultrawide linear response range. Here, we demonstrate a new e-skin sensor fabricated by introducing polyvinylpyrrolidone (PVP)-capped Ag nanowires into the chemically and physically cross-linked polyacrylamide–PVP double-network ethylene glycol organogel. The resulting organogel e-skin exhibits extreme stretchability (>22 000%), autonomous self-healing, as well as mechanical compliance. Particularly, the sensor is capable of antifreezing and antiheating (−20 to 80 °C) and provides an ultrawide linear response range with a gauge factor of 0.15 for 0–430% tensile strain and 0.71 for 430–18 100% tensile strain, respectively. By dynamically accommodating to a curved surface, the e-skin sensor demonstrates comprehensive applications in real-time and in situ tracking of large body deformations, spatial gesture movements, and physiological signals for motion behaviors and health level evaluation, showing great promise in wearable electronics, biomedical devices, and soft robotics.

Stretchable strain sensors offer great potential for diverse applications in modern electronics. However, it is still difficult to fabricate strain sensors with extreme stretchability, high stability, and superior durability because of the challenge in elastic matrix. In this work, the first example of extremely stretchable and highly stable double-networks ethylene glycol (EG) organogel is developed for the fabrication of wearable strain sensors with high performances. It is shown that the formation of hybrid physically and chemically cross-linked double-networks endows the EG organogel with an extraordinarily stretchability as high as 21 000%, which is the highest value for gels reported in the literature. Meanwhile, the low vapor pressure of EG gives the organogel high ambient stability. Benefiting from the intrinsic stretchability and stability of EG organogel, the strain sensors are fabricated easily by incorporating graphene as electrically conductive filler, which display extremely wide strain-sensing range (>10 500% fracture strain) with a gauge factor of 2.3. More importantly, the sensor can withstand >50 000 loading–unloading cycles in air, exhibiting high stability and superior durability. It is demonstrated that these sensors can track joint movements and muscle vibrations (such as human joint motions, drinking, saying, breathing, and slight cough) of human body and even distinguish the deformations of different directions and the touches of a hair. This work not only provided a new elastic matrix platform for the fabrication of extremely stretchable, stable, and durable strain sensors but also demonstrates their applications as wearable electronic devices for tracking both large and tiny motions of human body, which could be further extended to the practical applications in electronic skin, human–machine interactions, and personalized health monitoring.

Upon fertilization, drastic chromatin reorganization occurs during preimplantation development1 . However, the global chromatin landscape and its molecular dynamics in this period remain largely unexplored in humans. Here we investigate chromatin states in human preimplantation development using an improved assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq)2 . We find widespread accessible chromatin regions in early human embryos that overlap extensively with putative cis-regulatory sequences and transposable elements. Integrative analyses show both conservation and divergence in regulatory circuitry between human and mouse early development, and between human pluripotency in vivo and human embryonic stem cells. In addition, we find widespread open chromatin regions before zygotic genome activation (ZGA). The accessible chromatin loci are readily found at CpG-rich promoters. Unexpectedly, many others reside in distal regions that overlap with DNA hypomethylated domains in human oocytes and are enriched for transcription factor-binding sites. A large portion of these regions then become inaccessible after ZGA in a transcription-dependent manner. Notably, such extensive chromatin reorganization during ZGA is conserved in mice and correlates with the reprogramming of the non-canonical histone mark H3K4me3, which is uniquely linked to genome silencing3–5. Taken together, these data not only reveal a conserved principle that underlies the chromatin transition during mammalian ZGA, but also help to advance our understanding of epigenetic reprogramming during human early development and in vitro fertilization. By applying an optimized ATAC-seq protocol to human early embryos, distinct accessible chromatin landscapes are found before and after zygotic genome activation, revealing a marked epigenetic transition during zygotic genome activation and putative regulatory elements wiring human early development.

Pneumonia represents a public health problem of substantial health and economic burden. However, the evidence on the burden of adult pneumonia is limited in China.

Flexible and multifunctional microsensors have attracted wide attention owing to their multiple-sensing functions and diverse application fields. Here, we develop a series of highly flexible, multicolored, and multifunctional single-fiber-based (SFB) microsensors for flexible functional electronics. The SFB microsensors are based on the ingenious combination of single ZnO-coated carbon fiber (CF), flexible indium tin oxide/poly(ethylene terephthalate) (ITO/PET) membrane, and typing paper through a facile integration method. Specifically, a series of ZnO-coated CFs are prepared by chemically and coaxially depositing ZnO nanolayers on the CF surface through the atomic layer deposition (ALD) technique. Notably, the resultant SFB microsensors exhibit vivid and tunable structural colors originating from the thin-film interference of ZnO nanolayers as well as optical anisotropy because of the distinct axisymmetric structure of the CF. Benefiting from the optoelectronic properties of the ZnO nanolayer and delicate device structure, the SFB microsensors show a high UV sensitivity (120%) and good mechanical stability at varying bending angles (0–150°) and cycles (600 cycles). Moreover, by harnessing the pyroelectric and photothermal effects, the SFB microsensors can also be utilized to detect ambient temperature changes (0–55 °C) and IR light with high linearity, relatively high sensitivity (0.74% °C–1), and good stability. Owing to these merits, such SFB microsensors are capable of monitoring mouth respiration and nose breathing, implying their applications in wearable health monitors. This work not only integrates different sensing capabilities into a flexible device with reduced complexity but also miniaturizes the size of the device dramatically, holding tremendous prospects for diverse smart microsensing applications.

In this Letter, the ‘Open chromatin’ label in Fig. 4a should have been centred above the first three columns, and the black horizontal line underneath the label should have been removed. In addition, there should have been a vertical black line between the last two sets of panels for consistency. Minor changes have also been made to Fig. 1 and to the legend of Fig. 3. These errrors have been corrected online, and see Supplementary Information to the accompanying Amendment for the original Fig. 4.