Graphene, a two-dimensional carbon in honeycomb crystal with single-atom thickness, possesses extraordinary properties and fascinating applications. Graphene mechanics is very important, as it relates to the integrity and various nanomechanical behaviors including flexing, moving, rotating, vibrating, and even twisting of graphene. The relationship between the strain and stress plays an essential role in graphene mechanics. Strain can dramatically influence the electronic and optical properties, and could be utilized to engineering those properties. Furthermore, graphene with specific kinds of defects exhibit mechanical enhancements and thus the electronic enhancements. In this short review, we focus on the current development of graphene mechanics, including tension and compression, fracture, shearing, bending, friction, and dynamics properties of graphene from both experiments and numerical simulations. We also touch graphene derivatives, including graphane, graphone, graphyne, fluorographene, and graphene oxide, which carve some fancy mechanical properties out from graphene. Our review summarizes the current achievements of graphene mechanics, and then shows the future prospects.

With the intrinsic material advantages, silicon carbide (SiC) power devices can operate at high voltage, high switching frequency, and high temperature. However, for SiC wafers with high hardness (Mohs hardness of 9.5), the diamond blade dicing suffers from problems such as debris contaminants and unnecessary thermal damage. In this work, a precision layered stealth dicing (PLSD) method by ultrafast lasers is proposed to separate the semi-insulated 4H-SiC wafer with a thickness of 508 μm. The laser power attenuates linearly from 100% to 62% in a gradient of 2% layer by layer from the bottom to the top of the wafer. A cross section with a roughness of about 1 μm was successfully achieved. We have analyzed the effects of laser pulse energy, pulse width, and crystal orientation of the SiC wafer. The anisotropy of the SiC wafer results in various qualities of PLSD cross sections, with the roughness of the crystal plane {10−10} being 20% lower than that of the crystal plane {11−20}.

Hybrid perovskites have recently attracted attention in both materials science and opto-electronics research, because of their excellent opto-electronic properties and facile fabrication. Perovskite-based photovoltaic devices, photodetectors, and light-emitting diodes have exhibited unprecedented success. Moreover, optically pumped perovskite lasers have been reported with various crystal shapes. However, most of these lasers are fabricated from solution-grown micro/nano crystals, and thus lack reproducibility. Here, we present controllable fabrication of formamidinium lead iodide (FAPbI₃) perovskite microdisks by thermal co-evaporation, coupled with femtosecond laser direct writing. After careful investigation of dimensional effects, including the impact of diameter and thickness, we achieved an ultra-low threshold of ∼3 μJ cm⁻². Furthermore, we investigated the relationship of lasing performance with carrier dynamics by transient absorption. We found that a longer carrier lifetime can reduce the pump threshold. These microdisk lasers based on femtosecond laser fabrication of evaporated perovskite thin films show exceptional reproducibility, rendering them extremely suitable for mass production; hence, they offer a promising method for low-cost, on-chip coherent light sources.