High-resolution multicolor printing based on pixelated optical nanostructures is of great importance for promoting advances in color display science. So far, most of the work in this field has been focused on achieving static colors, limiting many potential applications. This inevitably calls for the development of dynamic color displays with advanced and innovative functionalities. In this Letter, we demonstrate a novel dynamic color printing scheme using magnesium-based pixelated Fabry-Pérot cavities by gray scale nanolithography. With controlled hydrogenation and dehydrogenation, magnesium undergoes unique metal and dielectric transitions, enabling distinct blank and color states from the pixelated Fabry-Pérot resonators. Following such a scheme, we first demonstrate dynamic Ishihara plates, in which the encrypted images can only be read out using hydrogen as information decoding key. We also demonstrate a new type of dynamic color generation, which enables fascinating transformations between black/white printing and color printing with fine tonal tuning. Our work will find wide-ranging applications in full-color printing and displays, colorimetric sensing, information encryption and anticounterfeiting.

The sharp Zn dendrites tend to pierce through the separator and result in a short circuit of the battery, which disables electronic devices. [3] Generally, Zn dendrites are easily formed on the common planar conductive hosts with low surface area due to their excessive local current density and unrestricted 2D diffusion of Zn 2+ . [4] Various strategies have been adopted to inhibit Zn dendrites growth, such as electrolyte optimization, [5] surface modification, [6] and structural design. [7] For electrolyte optimization, concentration control, "water in salt", and additives for electrostatic shielding are used to improve the performance of the battery. For surface modifications, there are several effective methods like atomic layered deposition, solution soaking, and slurry casting. From the structural design strategy, construction of 3D high-surface-area zinc anode is considered as an effective way to restrain the dendrite formation. [8] For instance, 3D sponge Zn, electrodeposited Zn nanostructures on 3D current collectors, and dual-channel porous Zn are proven to effectively inhibit Zn dendrite growth. The increased surface area of 3D conductive host can reduce local current density and homogenize interfacial charge distribu-

Metasurfaces enable the design of optical elements by engineering the wavefront of light at the subwavelength scale. Due to their ultrathin and compact characteristics, metasurfaces possess great potential to integrate multiple functions in optoelectronic systems for optical device miniaturisation. However, current research based on multiplexing in the 2D plane has not fully utilised the capabilities of metasurfaces for multi-tasking applications. Here, we demonstrate a 3D-integrated metasurface device by stacking a hologram metasurface on a monolithic Fabry–Pérot cavity-based colour filter microarray to simultaneously achieve low-crosstalk, polarisation-independent, high-efficiency, full-colour holography, and microprint. The dual functions of the device outline a novel scheme for data recording, security encryption, colour displays, and information processing. Our 3D integration concept can be extended to achieve multi-tasking flat optical systems by including a variety of functional metasurface layers, such as polarizers, metalenses, and others.

Metasurfaces hold great potentials for advanced holographic display with extraordinary information capacity and pixel sizes in an ultrathin flat profile. Dual-polarization channel to encode two independent phase profiles or spatially multiplexed metaholography by interleaved metasurfaces are captivated popular solutions to projecting multiplexed and vectorial images. However, the intrinsic limit of orthogonal polarization-channels, their crosstalk due to coupling between meta-atoms, and interleaving-induced degradation of efficiency and reconstructed image quality set great barriers for sophisticated meta-holography from being widely adopted. Here we report a non-interleaved TiO2 metasurface holography, and three distinct phase profiles are encoded into three orthogonal polarization bases with almost zero crosstalk. The corresponding three independently constructed intensity profiles are therefore assigned to trichromatic (RGB) beams, resulting in high-quality and high-efficiency vectorial meta-holography in the whole visible regime. Our strategy presents an unconventionally advanced holographic scheme by synergizing trichromatic colors and tri-polarization channels, simply realized with a minimalist non-interleaved metasurface. Our work unlocks the metasurface's potentials on massive information storage, polarization optics, polarimetric imaging, holographic data encryption, etc.Keywords: tri-polarization-channel metasurface; trichromatic vectorial holography; polarization conversion; non-interleaved metasurface; dielectric nanostructures. IntroductionSubwavelength metal or dielectric meta-units arranging in a two-dimensional plane form a metasurface, which can almost arbitrarily manipulate the wavefront such as amplitude, phase and polarization 1-3 . The complementary metal oxide semiconductor (CMOS) compatible fabrication process enables various metasurfaces components in the optical range that are more compact and perform better than conventional refractive optics, such as abnormal reflector/refractor 1, 4-6 , color filter 7, 8 , metalens 3, 9-11 , metahologram 12-14 , quantum metasurfaces 15-17 and multifunctional metasurfaces 18-21 .Multichannel metasurface-based devices have been extensively studied. One important application is to reconstruct full-color images. The crosstalk among different wavelengths is taken care of mainly by two approaches: optimized phase retrieval algorithm and judiciously optimized meta-atoms. The first approach enables a single phase profile to generate a color image by introducing position information in the phase retrieval processes to suppress the crosstalk among different operational wavelengths in the observation region [22][23][24] . However, unwanted images will be induced in other regions. On the other hand, the second approach is to provide wavelength-dependent phase profiles via carefully tailored meta-atoms 14,[25][26][27][28][29] , which can support wavelengthdependent responses. The meta-atom subarrays specifically designed for each given wavelength can be interleaved...

Pain‐perceptual nociceptors (PPN) are essential sensory neurons that recognize harmful stimuli and can empower the human body to react appropriately and perceive precisely unusual or dangerous conditions in the real world. Furthermore, the sensitization‐regulated nociceptors (SRN) can greatly assist pain‐sensitive human to reduce pain sensation by normalizing hyperexcitable central neural activity. Therefore, the implementation of PPNs and SRNs in hardware using emerging nanoscale devices can greatly improve the efficiency of bionic medical machines by giving them different sensitivities to external stimuli according to different purposes. However, current most‐normal organic/oxide transistors face a great challenge due to channel scaling, especially in the sub‐10 nm channel technology. Here, a sub‐10 nm indium‐tin‐oxide transistor with an ultrashort vertical channel as low as ≈3 nm, using sodium alginate bio‐polymer electrolyte as gate dielectric, is demonstrated. This device can emulate important characteristics of PPN such as pain threshold, memory of prior injury, and pain sensitization/desensitization. Furthermore, the most intriguing character of SRN can be achieved by tuning the channel thickness. The proposed device can open new avenues for the fascinating applications of next‐generation neuromorphic brain‐like systems, such as bio‐inspired electronic skins and humanoid robots.