Crawling robots are advantageous in overcoming obstacles. These robots have characteristics such as light weight and outstanding mobility. In case of large robots, they have difficulties passing narrow gaps or entering the cave. In this paper, we propose a milli-scale hexapedal robot using 4-bar linkages. Two conditions are necessary to enable efficient walking. In short, the trajectory of the foot must be elliptical, and the lowest point of the foot should be the same. These conditions are satisfied with a novel leg design. The robot has a pair of three legs and the legs are coupled to operate simultaneously. Each set of the legs are installed to robot’s both sides and the legs satisfy the equal lowest foot point and elliptical trajectory. As a result, this hexapedal robot can crawl with 0.56m/s speed.

Recently, the robotic hand sector is widely utilized throughout the entire machine industry, where gripping mechanism is gradually becoming more complex and standardized. In this study, studies were conducted to hold irregular, unstructured objects with simpler, more manageable operating principles based on compliant mechanics. In fact, it used the principle of buckling which is not commonly used in mechanical design to provide stable grasping force without giving any damage to objects with uncertain magnitude and rigidity. By using CFM(constant force mechanism) based on the principle of buckling, the force of the object and the contact surface is fixed evenly across the segments, providing a stable grasping force to the object. Also, a bar that serves as a linear guide prevents the hand from buckling to unwanted direction gives elaboration to the hand. With a simpler principle, the lower unit price and higher applicability, there is little friction in the mechanism, and it focused on creating a lightweight hand, which have significance for about 90% of excellent gripping performance.

본 연구는 사범대학 역사교육과의 <역사교과교재연구및지도법(한국사)>에서 ‘창의적인 역사 수업’을 모색한 예비 역사교사들의 교육적 경험을 고찰한 사례 연구이다. 연구 문제는 예비 역사교 사들이 ‘창의성’과 ‘창의적인 역사수업’에 대해 어떻게 생각하는가? 예비 역사교사들은 ‘창의적인 역사수업’을 위해 어떠한 고민과 노력을 하는가? 예비 역사교사들이 실현하고자 하는 ‘창의적인 역사수업’은 역사교과 내용의 특성을 어떻게 반영하는가? 예비 역사교사들의 창의 역량과 창의교수 자기효능감은 어떻게 변화하였는가?로 설정하였다. 연구의 결과 및 논의는 다음과 같다. 강의 초반, 연구 참여자들은 역사 수업에서의 창의성에 대해 모호함과 의구심을 가졌다. 그러나 강의 참여 과정에서 연구 참여자들은 ‘학생 중심의 능동적인 학습’을 구현하는 방향으로 창의적인 역사수업을 모색하였다. 그리고 강의 참여 이후에는 연구 참여자들의 ‘창의 역량’과 ‘창의교수 자기효능감’이 향상되었다. 주목되는 점은 연구 참여자들이 역사 교과 내용의 특성에 기반한 ‘능동적인 이해’를 중시하였다는 것이다. 또한, 연구 참여자들은 창의적인 역사수업을 위한 예비 역사교사의 소양으로 역사학 연구 지식과 사료 지식의 필요성을 느꼈다. 사범대학 역사교육과의 교육과정을 통해 예비 중등 역사교사들이 창의 교육에 대한 많은 고민과 실천의 기회를 갖는다면, 그들의 창의 역량이나 창의교수 자기효능감이 향상될 수 있을 것이다. 본 연구는 사례 연구로서 연구의 결과 및 논의를 일반화하기는 어렵지만, 그럼에도 불구하고 본 연구가 예비 중등 역사교사들의 창의 교육 역량 함양에 일조할 수 있기를 기대한다.

Milli-scale crawling robots have been widely studied due to their maneuverability in confined spaces. For successful crawling, the crawling robots basically required to fulfill alternating gait with elliptical foot trajectory. The alternating gait with elliptical foot trajectory normally generates both forward and upward motion. The upward motion makes the aerial phase and during the aerial phase, the forward motion enables the crawling robots to proceed. This simultaneous forward and upward motion finally results in fast crawling speed. In this paper, we propose a novel alternating mechanism to make a crab-inspired eight-legged crawling robot. The key design strategy is an alternating mechanism based on double four-bar linkages. Crab-like robots normally employs gear-chain drive to make the opposite phase between neighboring legs. To use the gear-chain drive to this milli-scale robot system, however, is not easy because of heavy weight and mechanism complexity. To solve the issue, the double-four bar linkages has been invented to generate the oaring motion for transmitting the equal motion in the opposite phase. Thanks to the proposed mechanism, the robot crawls just like the real crab with the crawling speed of 0.57 m/s.

A small and lightweight crawling robots have been actively studied thanks to their outstanding mobility and maneuverability. Those robots can navigate into more confined spaces that larger robots are unable to reach or enter such as debris and caves. In this paper, we propose a milli-scale hexapedal robot based on planar linkage design. To make this possible, two necessary conditions for successful crawling are satisfied: thrust force from the ground and aerial phase while running. These conditions are achieved through a newly developed leg design. The robot has a pair of legs and each leg has three feet. Those feet alternatively moves based on 1DOF planar linkage. This linkage is installed at each side of the robot and finally the robot shows the alternating gait and aerial phase during running. As a result, the robot runs with the crawling speed of 0.9 m/s.

In nature, many small insects are using jumping as a survival strategy. Among them, fleas jump in a unique method. They use an elastomer, 'Resilin’, an extensor muscle and a trigger muscle. By contracting the extensor muscle, the elastic energy, that makes a flea to jump, is stored in the resilin. After storing energy, the trigger muscle begins contracting and pulling the extensor muscle. When the extensor muscle crosses the rotational joint, direction of torque generated from the extensor muscle reverses, ‘torque reversal mechanism’. Simultaneously, the elastic energy stored in the resilin releases rapidly and is converted into the kinetic energy. It makes a flea to jump 150 times its body length. In this paper, miniaturized jumping robot using flea-inspired catapult mechanism is presented. This mechanism is based on the 4-bar linkage and the reversal joint and is actuated by Shape Memory Alloy (SMA) coiled springs describing the flea’s muscle. The robot prototype is fabricated by SCM process using glass fiber prepregs and a sheet of polyimide film. The prototype is 20mm link length, 34mm width and 2.0g weight and can jump 103cm.