Dormant plasticity of rotifer diapausing eggs in response to predator kairomones.

In freshwater ecosystems, hatching strategy of diapausing eggs (DEs) under predation risk has important ecological implication for zooplankters. Although kairomones released by predators can induce phenotypic responses of prey, hatching patterns of DEs in response to kairomones have received contradictory conclusions in zooplankters. Maternal environment may also affect hatching strategy of DEs during predator-prey interactions. We used classical Brachionus calyciflorus-Asplanchna models to determine the timing and proportion of DE hatching in association with parental and embryonic exposure to kairomones. Results obtained from two Brachionus clones supported the hypothesis that DEs could detect Asplanchna kairomones and adjust hatching patterns. DEs showed early and synchronous hatching patterns in the environment with kairomones. Data also supported the prediction that DEs could gain information about predators from maternal environments and adjusted their hatching pattern in response to the presence of kairomones. Compared with DEs from Brachionus mothers not exposed to kairomones, DEs produced by mothers that were experienced with kairomones attained a higher hatching rate when both of them hatched in the environment either with or without kairomones. Our results suggest that DEs of B. calyciflorus possess dormant plasticity to defend against predation from Asplanchna, which may be regulated by maternal environmental effects during sexual life cycles.

Research on MEMS Solid-State Fuse Logic Control Chip Based on Electrical Explosion Effect.

A microelectromechanical systems (MEMS) solid-state logic control chip with three layers-diversion layer, control layer, and substrate layer-is designed to satisfy fuse miniaturization and integration requirements. A mathematical model is established according to the heat conduction equation, and the limit conditions of different structures are presented. The finite element multi-physical field simulation method is used to simulate the size and the action voltage of the diversion layer of the control chip. Based on the surface silicon process, fuse processing, and testing with the MEMS solid-state fuse-logic control chip, a diversion layer constant current, maximum current resistance test, and a control layer of different bridge area sizes, the bridge area size is 200 × 30 µm, and the minimum electrical explosion voltage is 23.6 V. The theoretical calculation results at 20 V and 100 µF demonstrate that the capacitor energy is insufficient to support the complete vaporization of the bridge area, but can be partially vaporized, consistent with the experimental results.

Study on Characteristics of Electromagnetic Coil Used in MEMS Safety and Arming Device.

Traditional silicon-based micro-electro-mechanical system (MEMS) safety and arming devices, such as electro-thermal and electrostatically driven MEMS safety and arming devices, experience problems of high insecurity and require high voltage drive. For the current electromagnetic drive mode, the electromagnetic drive device is too large to be integrated. In order to address this problem, we present a new micro electromagnetically driven MEMS safety and arming device, in which the electromagnetic coil is small in size, with a large electromagnetic force. We firstly designed and calculated the geometric structure of the electromagnetic coil, and analyzed the model using COMSOL multiphysics field simulation software. The resulting error between the theoretical calculation and the simulation of the mechanical and electrical properties of the electromagnetic coil was less than 2% under the same size. We then carried out a parametric simulation of the electromagnetic coil, and combined it with the actual processing capacity to obtain the optimized structure of the electromagnetic coil. Finally, the electromagnetic coil was processed by deep silicon etching and the MEMS casting process. The actual electromagnetic force of the electromagnetic coil was measured on a micro-mechanical test system, compared with the simulation, and the comparison results were analyzed.