Xia Dong

Laser-induced graphene: preparation, functionalization and applications

Abstract Recently graphene-based materials (GBMs) have gained tremendous attention for their enormous potentials for various functional devices due to their excellent physical and chemical properties. However, the cost effective synthesis and patterning of carbon nanomaterials are a challenge, which significantly restricts its applications. Therefore, straightforward preparation and processing of GBMs in a scalable approach is still a important goal. In recent years, laser direct writing (LDW) technique provides a powerful processing method for the broad application of laser-induced graphene (LIG) which does not rely on either high temperature or toxic chemicals. This article aims to update the latest results in this rapidly evolving field and to provide critical insights to inspire more exciting developments of LIG and its functionalization. Based on the interaction mechanisms and physical effects, we comparatively review the methods of preparation and functionalization of LIG, including inducing, structuring, doping and hybriding. In this progress report, the applications of LIG and its GBMs patterned by LDW technique were discussed in the fields of optoelectronic devices, energy storage devices, biosensors and biomimetic devices.

The influence of pre-melting in laser drilling with temporally modulated pulse

ABSTRACT Laser drilling by temporally modulated pulse is a promising technique and has many advantages compared with normal pulse drilling. In this work, the effect of modulated pulse comprising pre-heating front and sharp trail was mainly studied. The function of the former was to pre-melt the radiated material, and the latter was to expel the liquid melt from the molten pool, thus to form a blind hole. While the trail subpulse was kept constant, the difference in the pre-heating subpulse parameter could cause a considerable influence on the hole quality and drilling efficiency. The depth and volume of the molten pool were proportional to the pre-heating energy, and inversely proportional to the pre-heating duration. With pre-heating subpulses of proper parameters, the sharp trail subpulse was very effective in expelling the melt liquid, leaving only a small quantity of melt to re-solidify as the recast layer, which was observably thinner compared with the holes drilled using the normal pulse mode. In the pre-melting process, the directional melt flow and heat conduction were found to be the reasons why the deep melting phenomenon had occurred.

Perception System Design of Virtual Human by Object-Oriented Method

The perception module system of the virtual human in dangerous circumstances is studied mainly. The decision-making model based on emotion is created with mathematical method. The visual perception method is designed with geometrical algorithm, which can realize the determination of objects’ visibility. Perception module is designed with object-oriented method, including environment-information notification and virtual human’s responser. Communication between virtual human and nearby objects is communicated based on the perception module. The platform, which can simulate virtual human behaviors, is created with OpenGL technology by Visual C++6.0. The simulation results of virtual human behaviors prove that the perception system design of the virtual human is feasible.