Lei Liu

The advancement of electronic skins toward commercialization calls for cost-effective and robust flexible conductors, among which metal films are attractive candidates but suffer from poor stretchability. Conventionally, cracks formed in strained metal films are universally considered detrimental and sought to be suppressed. Herein, we demonstrate that cracking is not a drawback, but rather an effective design parameter for on-demand tailoring of film properties. By exploiting the size effect in crack engineering, we propose a bioinspired, dual-scale architecture that endows metal film conductors with up to 325% stretchability. We show that through the synergy of nanoscale pore implantation and microscale substrate roughening, progressively evolved crack patterns can be programmed within metal films by modulating structural parameters. This tunable film cracking behavior yields a nearly 25-fold regulation of stretchability, representing a remarkably wide tunable range among previously deposited metal counterparts. Leveraging these advances, a stretchable metal film-based, AI-empowered electronic skin is constructed, demonstrating excellent practicality across diverse flexible sensing scenarios. Our strategy highlights the pivotal role of the size effect in precise crack manipulation, and the multi-scale regulation paradigm establishes a fresh route to performance improvement of flexible conductors.

To develop artificial intelligence and humanoid robotics, it is crucial to fabricate advanced vision systems with high efficiency and versatility. A key challenge is the functional integration of high-speed photodetectors (PD) and neuromorphic vision sensors (NVS) into a single device, as current studies suffer from complex architectures or fabrication processes. Hence, we propose a universal Microzone Femtosecond Laser Deposition (M-FLD) technique that enables the localized, in situ deposition of zero-dimensional (0D) black phosphorus (BP) nanoparticles onto a two-dimensional (2D) MoS ₂ channel by ablating a micro-scale solid-state target. By M-FLD and h-BN nanomask, we fabricated a spatial asymmetric 0D/2D heterostructure for highly integrated dual-mode optoelectronic device. By changing the direction of V _ds , the device can be converted from PD to NVS. Under the PD mode, the device can sense high-frequency optical signals up to 3030 Hz. Under the NVS mode, the device’s optical energy consumption per activity is only 191.2 pJ. Based on the sensing and memory capabilities, the device is simulated for MNIST handwritten digit recognition, achieving an accuracy of up to 96.20%. This work provides a flexible and powerful platform for fabricating complex heterostructures, paving the way for highly integrated and reconfigurable neuromorphic vision systems.

The trend toward ultimate edge computing systems requires a paradigm shift from integrating individual components to intrinsic multifunctional devices. However, a primary challenge lies in engineering a single device capable of harvesting energy, sensing complex environmental information, and performing on-device computation without overcomplicated device configuration. Herein, we address the challenge by developing a single-step, facile, ultrafast laser-induced symmetry engineering (LISE) process to fabricate a self-powered, polarization-sensitive neuromorphic vision device in a single MoTe₂-based architecture. By engineering the localized phase transition, we achieve simultaneous symmetry engineering of both the energy band and crystal structures. This dual asymmetry allows for self-powered operation via a built-in photovoltaic effect and polarization sensitivity from the engineered crystal anisotropy. Leveraging the photovoltaic volatile memory, an engineered FeFET operating as a physical reservoir achieves fully self-powered and all-optical reservoir computing for underwater imaging. Computation can be actively modulated by the polarization state of incident light and preconditioned by gate voltage, revealing a powerful hardware-level method for tuning computation. The proposed LISE approach demonstrates the ultrafast laser as a powerful tool for the local manipulation of material-symmetry-related properties and facilitates the creation of high-performance multifunctional neuromorphic systems.

Thermal performance of passive heat spreader vapor chambers is mainly determined by the performance of evaporation, which is highly dependent on the permeability of wicks. Most existing studies on wick permeability focus on the wick itself, while the effects of fabrication and assembly processes are often overlooked. In this paper, accurate V-shape microgrooves were fabricated by femtosecond laser efficiently with a diffractive optic element, and their capillary behavior was experimentally characterized using de-ionized water. A theoretical model was developed to describe liquid transport in such geometries, and finite-element simulations further validated the theoretical predictions. In addition, the degradation of permeability during heat treatment and prolonged air exposure was systematically investigated, and an effective recovery method was proposed. This finding provides a framework for optimizing groove fabrication and preserving wick performance during vapor chamber manufacturing.

The impact of drops on solid surfaces is a common occurrence in natural systems, with a particular focus on reducing contact time during impingement for applications such as deicing and condensation heat transfer. While studies have reported that superhydrophobic single-ridge and some crossed-ridge textures can effectively reduce contact time, the effect of the ridge structure on the force between impinging drops and substrates remains unexplored. In this study, we employ high-precision force measurements to directly measure the dynamic forces during drop impact on superhydrophobic surfaces featuring a single-ridge structure. Temporal evolution profiles of impact forces reveal double peaks corresponding to the spreading and retraction processes. At lower Weber numbers within a specific range, a propagating surface wave from the bottom to the top of the drop is observed, resulting in intricate force-time profiles. We reveal that the spreading process of the drop is primarily influenced by decelerating inertia upon surface contact with capillary forces becoming more prominent at lower Weber numbers. Moreover, the second peak force is attributed to the momentum transfer of the liquid from the ridge-aligned horizontal direction to the vertical direction. Notably, the second peak force on ridged surfaces is significantly reduced compared to that on flat surfaces due to the reduced liquid volume involved in the retraction process. The study offers valuable insights into the potential regulation of impact forces.