A film-linked electrostatic self-assembly microfluidic chip.

This article proposes a film-linked electrostatic self-assembly microfluidic chip for the first time, designed to be ready-to-use. Barrier films are used to isolate the gas/liquid path microchannels and the pre-stored reagents of the chip before use. Through the linkage design between the film materials, the motion of barrier films is linked to the structural changes inside the chip. Under the combined action of the rebound force of the elastic substrate, the electrostatic adsorption force between the substrates, and the reaction force of the elastic film, the elastic substrate and the liquid storage substrate are instantly bonded, and the self-assembly of the chip is completed within 1 s. By using six independently output programmable sequences to perform the sequential quantitative pumping of pre-stored reagents, the transfer and mixing of samples and pre-stored reagents are automatically driven in a confined space, which greatly reduces the contamination risk and loss rate of samples/reagents, and improves the accuracy and reproducibility of test results. In addition, the microfluidic multi-step reaction driven in parallel can avoid liquid reflux, accurately control the amount of reactant transfer, and realize the quantitative detection of samples. Multiple reactions can be performed synchronously without interference, saving the test time. Since each gas path is independently controllable, the chip can be extended to a variety of biochemical reactions and has the potential to detect a variety of substances.

Motion Plan of Maritime Autonomous Surface Ships by Dynamic Programming for Collision Avoidance and Speed Optimization.

Maritime Autonomous Surface Ships (MASS) with advanced guidance, navigation, and control capabilities have attracted great attention in recent years. Sailing safely and efficiently are critical requirements for autonomous control of MASS. The MASS utilizes the information collected by the radar, camera, and Autonomous Identification System (AIS) with which it is equipped. This paper investigates the problem of optimal motion planning for MASS, so it can accomplish its sailing task early and safely when it sails together with other conventional ships. We develop velocity obstacle models for both dynamic and static obstacles to represent the potential conflict-free region with other objects. A greedy interval-based motion-planning algorithm is proposed based on the Velocity Obstacle (VO) model, and we show that the greedy approach may fail to avoid collisions in the successive intervals. A way-blocking metric is proposed to evaluate the risk of collision to improve the greedy algorithm. Then, by assuming constant velocities of the surrounding ships, a novel Dynamic Programming (DP) method is proposed to generate the optimal multiple interval motion plan for MASS. These proposed algorithms are verified by extensive simulations, which show that the DP algorithm provides the lowest collision rate overall and better sailing efficiency than the greedy approaches.