Despite attempts in a number of studies to utilize muscle tissue and cells as microactuators, all of the biohybrid microdevices have been operable only in the culture medium and none have worked in air due to the dry environment. This paper demonstrates an atmospheric-operable bioactuator (AOB) fabricated by packaging an insect dorsal vessel (DV) tissue with a small amount of culture medium inside a capsule. The AOB, consisting of microtweezers and the capsule, was designed based on a structural simulation that took into account the capillary effect. The base part of the microtweezers was deformed by spontaneous contractions of the DV tissue in the medium inside the capsule, by which the front edges of the microtweezer arms projecting above the medium surface were also deformed. First, we confirmed in the medium that the DV tissue was able to reduce the gap between the arm tips of the microtweezers. After taking the AOB out of the medium, as we expected, the AOB continued to work in air at room temperature. The gap reduction in air became larger than the one in the medium due to a surface tension effect, which was consistent with the simulation findings on the surface tension by the phase-field method. Second, we demonstrated that the AOB deformed a thin-wall ring placed between its tips in air. Third, we measured the lifetime of the AOB. The AOB kept working for around 40 minutes in air, but eventually stopped due to medium evaporation. As the evaporation progressed, the microtweezers were pressed onto the capsule wall by the surface tension and opening and closing stopped. Finally, we attempted to prevent the medium from evaporating by pouring liquid paraffin (l-paraffin) over the medium after lipophilic coating of the capsule. As a result, we succeeded in prolonging the AOB lifetime to more than five days. In this study, we demonstrated the significant potential of insect muscle tissue and cells as a bioactuator in air and at room temperature. By integrating insect tissue and cells not only into a microspace but also onto a substrate, we expect to realize a biohybrid MEMS device with various functions in the near future.

Industries need to concurrently evaluate productivity and energy consumption when designing and improving manufacturing systems. Manufacturing system simulations to evaluate productivity have often been used. However, manufacturing system simulations to concurrently evaluate productivity and energy consumption have not been proposed. The purpose of our research is to establish a system for concurrent evaluation of productivity and energy consumption in a manufacturing system simulation. First, in this study, necessary items and requirements to evaluate productivity and energy consumption are analysed. Secondly, a prior evaluation system considering the necessary items and the requirements is proposed. A state transition model for facilities, a simulation system and a visualization system are proposed to realize the prior evaluation system. Finally, case studies for a small-scale machining line and a middle-scale semiconductor manufacturing line are carried out to confirm the efficiency of our proposed prior evaluation system.

Industries need to design and improve their manufacturing systems while considering energy consumption and productivity concurrently. Manufacturing system simulation is often used to evaluate productivity when manufacturing systems are designed or improved. However, it is difficult to use simulation to evaluate energy consumption when designing and improving manufacturing systems. The purpose of our research is to establish a system for the concurrent evaluation of energy consumption and productivity in manufacturing system simulation. In this paper, first, requirements for a simulation to evaluate energy consumption and productivity are analyzed. Second, an evaluation system is proposed in consideration of the requirements. A Unified Modeling Language (UML) model that defines facility state transitions and relationships between the facility state and energy consumption is proposed. A manufacturing system simulation implemented in the proposed UML model is also proposed and developed. The proposed simulation is also implemented in a function to concurrently generate information on production throughput and energy consumption along a time progression. A system that provides a function to visually evaluate dynamic changes in the energy consumption per unit of production throughput along a time progression is also proposed and developed. Finally, a case study for semiconductor manufacturing systems is carried out to confirm the efficiency of our proposed evaluation system.

Industries need to evaluate productivity and energy consumption concurrently when designing and improving manufacturing systems. Manufacturing system simulation to evaluate productivity was often used. However, manufacturing system simulation to evaluate productivity and energy consumption concurrently was not proposed. The purpose of our research is to establish manufacturing system simulation for productivity and energy consumption. In this paper, first, requirements for manufacturing system simulation are analyzed. Second, functions considering analyzed requirements are proposed. The functions are a state transition model for facilities, a simulation system, and an evaluation system. Third, a manufacturing system simulation environment which is implemented the functions is also proposed. Finally, case studies for a small scale machining line and a middle scale semiconductor manufacturing line are carried out to confirm the efficiency of our proposed simulation.

To safely use of hydrogen utilization machines after large earthquakes, the effect of multiple overloads and hydrogen on high-cycle fatigue strength of SUS304 and SUS316L austenitic stainless steels were evaluated. Three kinds of notched fatigue test specimens which have different notch root radius were used. The fatigue strength of both materials was significantly reduced by multiple overloads. The cause was small cracks formed by the overloads. In SUS304, the reduction of fatigue strength became more significant by hydrogen. The cause was that hydrogen accelerated propagation of the small cracks during overloading. On the other hand, fatigue strength of SUS316L was insusceptible to hydrogen. Propagation of the small cracks existing notch root was evaluated by plastic strain range at notch root and Manson-Coffin rule in order to consider application of this study for design.