• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.4
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• pp.269-274
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• 1999

A bending actuator using zigzag type shape memory alloy springs has been fabricated and characterized. The fabricated millimeter-sized actuator has outer diameter of 3.0mm and inner diameter of 2.0mm. The zigzag type spring is more suitable for thin wall type actuator because the zigzag type spring has a planar structure comparing with the coil type spring which has a three-dimensional structure. The measured characteristics of the fabricated bending actuator show the possibility of practical application to micro active bending catheters.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2512-2514
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• 1998

The bending actuator using zigzag type shape memory alloy springs has been fabricated and characterized. The small sized actuator with outer diameter of 3.0mm and inner diameter of 2.0mm could be implemented because zigzag type spring has advantages for thin wall type actuator over the coil type spring. The measured characteristics of the fabricated bending actuator show the possibility of practical application to micro active bending catheter.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.1071-1074
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• 1995

This paper proposes two directional bending actator using three link, two shape memory alloys(SMA) of coil-type springs and two guide wires. By the heating of two SMA springs sequentially, the bending and stretching of the actuator is possible. Bending angle, force and repeated bending motion of actuator were measured and characterized. The performance of the actuator has been characterized for the possible application for catheter.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.1
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• pp.47-52
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• 2013

In order to operate a search and rescue robot in hazardous area, the robot requires high mobility and adaptable locomotion for moving in unpredictable environments. In this paper, we propose the deformable soft wheel robot that can produce three kinds of driving modes; caterpillar driving mode, normal wheel driving mode, legged-wheel driving mode. The robot changes its driving mode as it faces the various obstacles such as a small gap, stairs etc. Soft film and composite materials are used for fabrication of deformable wheel structure and Shape Memory Alloy (SMA) coil spring actuators are attached on the structure as an artificial muscle. Film lamination and an composite manufacturing process is introduced and the robot design is required to be modified and compromised to applying the manufacturing process. The prototype is developed and tested for verifying feasibility of the deformable wheel locomotion.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.12
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• pp.1301-1307
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• 2011

Electrosurgical knee wand (EKW) is a high-frequency thermocautery instrument and is often used for coagulation, ablation, excision, and extirpation of knee ligaments and tissues. In order to maximize the success rate, ease, and safety of knee surgery using EKW and radiofrequency ablation, it is necessary to ensure that the EKW selectively approaches the lesion with utmost accuracy and safety. The key feature of this instrument is its excellent maneuverability. Hence, the authors constructed a tensile spring model based on a shape memory alloy (SMA), which exhibits the shape memory effect. This model can be used in knee surgery as it is considered the most biocompatible femorotibial surgical actuator. The changes in external temperature with current and the thermoelectric characteristics of the SMA were investigated. The relationship between the restoring force and the typical stroke (TS) in response to the conditions in the SMA tensile spring design were evaluated. In conclusion, as the diameter of the SMA tensile spring decreased, the maximum temperature increased. The strain in the actuator caused a stable and proportional increase in the force and induced current for up to 15s, but this increase became very unstable after 30s. Moreover, the relationship between the current and the TS was more stable than that between the current and the restoring force.