• 한국정밀공학회지
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• 제14권8호
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• pp.130-136
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• 1997

For compensating the error motion of hydrostatic guideways, we introduce a way that the clearance of table is actively controlled corresponding to the amount of error with the variable capillary. The structure and the theoretical design method of active controlled capillary using piezo actuator, named ACC, are proposed in this paper. Basic characteristics such as the maximum controllable range, micro step response and available dynamic bandwidth are tested for confirmation of structural suitability of ACC, and these characteristics are also tested on the table mounted with ACC for verifying the availability. The experimental result showed that by the use of ACC, the error motion within 2.7 .mu. m of a hydrostatic guideway can be compensated with the resolution of 2.7nm, 1/100 contollable range, and the frequency bandwidth of 5.5 Hz. From these results, it is confirmed that the ACC is very effective to improve the motion accuracy of high or ultra precision hydrostatic guideways.

• 한국정밀공학회지
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• 제22권2호
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• pp.180-187
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• 2005

This paper is focused on the development of the flexible electrode for disc-type polymer actuators using Segmented Polyurethane(SPU). This paper consists of two parts. The one is about the mechanical property such as elastic modulus. these parameters mainly affect behaviors of polymer actuators and the other is about the electro-chemical property such as the surface resistance of the composite electrode affects the strength of electrostatic force, results in the deformation of polymer actuators. The Young's modulus was measured by UTM. As result, by increasing the modulus of a body of polymer actuators, the maximum displacement of polymer actuators are decreased. The surface resistance of the electrode was measured by 4 point probe system. Compared with the conductive silver grease, the displacement of polymer actuators using carbon black(CB) composite electrodes is comparably small but CB composite electrode should be the practical approach for the improvement of the performance of all-solid actuators, compared with another types of electrode materials.

• Journal of Mechanical Science and Technology
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• 제20권11호
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• pp.1914-1919
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• 2006

Recently, the microrobots powered by biological muscle actuators were proposed. Among the biological muscle actuators, frog muscle is well known as a good muscle actuator and has a large displacement, actuation forces and piezoelectric properties. Therefore, for the application of the biomimetic microrobot, this paper reports the electromechanical properties of frog muscle. First of all, the experimental setup has been established for measuring generative force of the frog muscle. Through the various electrical stimulating inputs to the frog muscle, we measured the contractile force of the frog muscle. From the measuring results, we found that the actuating contractile force responses of the frog muscle are determined by the amplitude, frequency, duty ratio, and wave form of the stimulation signal. This study will be beneficial for the development of the microrobot actuated by frog muscle.

• 한국정밀공학회지
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• 제20권12호
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• pp.64-72
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• 2003

This paper presents a small loading and positioning device using VCM (voice coil motor). The developed device consists of a VCM-based linear actuating system, a capacitance displacement sensor and a cantilever deflection sensing system. The trust force of the VCM proportional to applied current moves the column supported on two pairs of parallel leaf springs. The infinitesimal displacement of moved column is detected by capacitance displacement sensor with a resolution of 0.1nm and a repeatability of 1nm. Also, a micro cantilever with known stiffness (200N/m), which is mounted on the end of the column, is used as a force sensor to detect the load applied to a specimen. After the cantilever contacts with the specimen, the deflection of cantilever and the load applied to the specimen are measured by using an optical lever system which consists of a diode laser, a mirror and a PSD (position sensitive detector). In this paper, an experimental system was constructed and its actuator and sensing parts were tested and calibrated. Also, the constructed system was applied to the indentation experiment and the load-displacement curve of aluminum was obtained. Experimental results showed that the developed device can be applied for performing nano indentation.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.1157-1164
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• 2003

Dynamic Load/unload (L/UL) mechanism is an alternative to the contact start stop (CSS) technology which eliminates stiction and wear failure modes associated with CSS. Other benefits of L/UL include increased areal density due to smooth disk surfaces, thinner overcoats, and lower head flying height Improved shock resistance due to elimination of head slap, and reduced power consumption. Inertia latch mechanism becomes important for mobile disk drives because of non operating shock performance. Various types of latch designs have been introduced in hard disk drives to limit a rotary actuator from sudden uncontrolled motion. In this paper, a single spring inertia latch is introduced for a small form optical disk drive, which uses a rotary actuator for moving an optical pick-up. A new small inertia latch with single spring is designed to ensure both feasible and small size. The shock performance of the new inertia latch is experimentally verified.

• 한국전기전자재료학회논문지
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• 제34권6호
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• pp.401-415
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• 2021

Soft robots are promising devices for applications in drug delivery, sensing, and manufacturing. Traditional hard robotics are manufactured with rigid materials and their degrees of motion are constrained by the orientation of the joints. In contrast to rigid counterpart, soft robotics, employing soft and stretchable materials that easily deforms in shape, can realize complex motions (i.e., locomotion, swimming, and grappling) with a simple structure, and easily adapt to dynamic environment. Among them, the magnetic actuators exhibit unique characteristics such as rapid and accurate motion control, biocompatibility, and facile remote controllability, which make them promising candidates for the next-generation soft robots. Especially, the magnetic actuators instantly response to the stimuli, and show no-hysteresis during the recovery process, essential for continuous motion control. Here, we present the state-of-the-art fabrication process of magnetically controllable nano-/micro-composites, magnetically aligning process of the composites, and 1-dimensional/multi-dimensional multimodal motion control for the nextgeneration soft actuators.

• Steel and Composite Structures
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• 제32권5호
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• pp.671-686
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• 2019

Active control of solar panels with honeycomb core and carbon nanotube reinforced composite (CNTRC) facesheets for smart structures using piezoelectric patch sensor and actuator to reduce the amplitude of vibration is a lack of the previous study and it is the novelty of this research. Of active control elements are piezoelectric patches which act as sensors and actuators in many systems. Their low power consumption is worth mentioning. Thus, deriving a simple and efficient model of piezoelectric patch's elastic, electrical, and elastoelectric properties would be of much significance. In the present study, first, to reduce vibrations in composite plates reinforced by carbon nanotubes, motion equations were obtained by the extended rule of mixture. Second, to simulate the equations of the system, up to 36 mode shape vectors were considered so that the stress strain behavior of the panel and extent of displacement are thoroughly evaluated. Then, to have a more acceptable analysis, the effects of external disturbances (Aerodynamic forces) and lumped mass are investigated on the stability of the system. Finally, elastoelectric effects are examined in piezoelectric patches. The results of the present research can be used for micro-vibration suppression in satellites such as solar panels, space telescopes, and interferometers and also to optimize active control panel for various applications.

• 대한기계학회논문집B
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• 제36권5호
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• pp.539-543
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• 2012

셀룰로오스 EAPap 작동기는 생체 모방형 작동기의 하나로 생체적합하고 가볍고 비교적 낮은 전압에서도 큰 변위를 발생시킨다는 장점을 가지고 있다. 셀룰로오스를 재생하면서 셀룰로오스 파이버를 배열함으로써 압전 종이를 만들었다. 한편 셀룰로오스에 탄소나노튜브, 산화금속 나노분말, 전도성 고분자, 이온성 유체등을 물리적, 화학적으로 결합시켜 다양한 하이브리드 나노복합재를 만들었다. 본 논문에서는 셀룰로오스 EAPap 의 제조공정 및 이를 응용한 바이오센서, 화학센서, 유연트랜지스터, 그리고 작동기의 응용 디바이스에 대해 소개한다. 또한 셀룰로오스 EAPap 을 무선으로 구동하는 기술에 대해 소개한다. 이는 생체모방로봇, 정찰 등에 활용될 수 있다.

• 한국전기전자재료학회논문지
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• 제25권1호
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• pp.62-67
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• 2012

Owing to the rapid growth of mobile and electronic equipment miniaturization technology, the supply of micro mobile computing machine has been fast raised. Accordingly they have performed many researches on energy harvesting technology to provide promising power supply equipment to substitute existing batteries. In this paper, in order to have low resonance frequency for piezoelectric energy harvester, we have tried to make it larger than before by adopting nickel that has much higher density than silicon. We have applied it for our energy harvesting actuator instead of the existing silicon based actuator. Through such new concept and approach, we have designed energy harvesting device and made it personally by making with micromachining process. The energy harvester structure has a cantilever type and has a dimension of $10{\times}2.5{\times}0.1\;mm^3$ for length, width and thickness respectively. Its electrode type is formed by using Au/Ti of interdigitate d33 mode. The pattern size and gap size is 50 ${\mu}m$. Based on the measurement of the nickel-based piezoelectric energy harvester, it is found to have 778 Hz for a resonant frequency with no proof mass. In that resonance frequency we could get a maximum output power of 76 ${\mu}W$ at 4.8 $M{\Omega}$ being applied with 1 g acceleration.

• 한국항공우주학회지
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• 제35권4호
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• pp.302-307
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• 2007

본 연구에서는 이온성 폴리머-금속 복합재료 (IPMC) 작동기를 사용한 플랩 밸브 마이크로 펌프의 설계, 제작 및 실험적 특성 규명을 수행하였다. 나피온/실리케이트 층과 나피온/실리카 나노복합재료를 기반으로 한 다층형 IPMC를 마이크로 펌프의 작동층으로 사용하였다. 마이크로 펌프의 핵심 요소인 IPMC 다이아프램의 주위를 유연한 폴리디메틸실옥산(PDMS)을 사용하여 지지하도록 함으로써 상당히 큰 작동 변위를 내도록 설계하였다. 이렇게 개발된 마이크로 펌프의 크기는 $20{\times}20{\times}5$ ${mm}^3$ 이고, 최대 유량은 760 l/min, 최대 배압은 1.5 kPa이었다. 본 연구에서 개발한 마이크로 펌프는 간단하고 효율적인 설계를 수행하여 제작이 용이할 뿐 아니라, 동작 전압이 1-3V라는 장점이 있다.