• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 춘계학술대회 논문집
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• pp.462-465
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• 2009

Cellulose based electro-active paper (EAPap) is a new smart material that has a potential to be used in biomimetic actuator and sensor. Beside of the natural abundance, cellulose EAPap is fascinating with its biodegradability, lightweight, high mechanical strength and low actuation voltage. An actuating mechanism of EAPap is revealed to be the combination of ion migration effect and piezoelectricity. EAPap can generate the electrical current and voltage when the mechanical stress applied due to its electro-mechanical characteristics. In this paper, we investigated the feasibility of EAPap as a mechanical strain sensor.

• 한국정밀공학회지
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• 제19권8호
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• pp.147-154
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• 2002

In this paper, a path navigation algorithm through use of a sensor platform is proposed. The sensor platform is composed of two electric motors which make panning and tilting motions. An algorithm for computing a real path and an obstacle length is developed by using a scanning method that controls rotation of the sensors on the platform. An Autonomous Robot Vehicle(ARV) can perceive the given path by adapting this algorithm. A sensor scanning method is applied to the sensor platform for using small numbers of sensor. The path navigation algorithm is composed of two parts. One is to perceive a path pattern, the other is used to avoid an obstacle. An optimal controller is designed for tracking the reference path which is generated by perceiving the path pattern. The ARV is operated using the optimal controller and the path navigation algorithm. Based on the results of actual experiments, this algorithm for an ARV proved sufficient for path navigation by small number of sensors and for a low cost controller by using the sensor platform with a scanning method.

• 한국정밀공학회지
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• 제31권2호
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• pp.157-164
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• 2014

In this paper, we design a gripping force control system using tactile sensor to prevent slip when gripper tries to grasp and lift an object. We use a flexible tactile sensor for measuring uniplanar pressure on gripper's finger and develop an algorithm to detect the onset of slip using the sensor output. We also use a flexible pressure sensor to measure the normal force. In addition, various signal processing techniques are used to reduce noise included in the sensor output. A 3-finger gripper is used to grasp and lift up a cylindrical object. The tactile sensor is attached on one of fingers, and sends output signals to detect slip. Whenever the sensor signal is similar to the slip pattern, gripper force is increased. In conclusion, this research shows that slip can be detected using the tactile sensor and we can control gripping force to eliminate slip between gripper and object.

• 대한기계학회논문집A
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• 제26권7호
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• pp.1288-1295
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• 2002

The column-type sensing element in building and mechanical construction parts was designed as three forces and three moments sensor by attaching strain gages approximately. Compared to conventional multi-component sensor, the designed sensor has high stiffness and low cost. The radius of the column was designed analytically and compared with finite element analysis. The interference errors between components were minimized by using addition and subtraction procedure of signals. The fabricated sensor was tested by using a deadweight force standard machine and a six-component force calibration machine. The calibration results showed that the 6-component forces and moments sensor had interference error less than 7.3 % between $F_x$ and $M_x$ components, and 5.0 % in case of other components.

• 열처리공학회지
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• 제36권4호
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• pp.237-241
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• 2023

Recently, research on flexible sensors for personal health management has been gaining attention. In this study, we fabricated a crack-based flexible sensor in thin film form to measure the pulse on the wrist. We evaluated the characteristics of the sensor based on the curing conditions of the PDMS (Polydimethylsiloxane) film to optimize the sensor's gauge factor. The modulus of PDMS varies depending on the curing conditions. In this case, the modulus of PDMS has a significant influence on crack formation, leading to changes in the sensitivity of the sensor. This study examined the changes in the gauge factor associated with these variations.

• 대한기계학회논문집A
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• 제39권6호
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• pp.603-610
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• 2015

본 논문에서는 기울기 센서와 고도계 센서로 구성된 다중모드 센서를 통하여 일정 공간내의 거주자의 자세 및 행동 패턴을 수집, 분석하여 거주자의 위치를 추론함으로써, 현재 거주자가 위치한 공간을 인지하는 시스템을 제안한다. 여기에서 제안된 센서 시스템의 하드웨어 구성과 소프트웨어 알고리즘에 대하여 설명하고, 다중모드 센서를 통하여 획득한 데이터로부터 거주자의 자세 및 행동을 분석한 후에 거주자가 존재하는 공간을 추론하는 프로세스에 대하여 설명한다. 마지막으로 거주자의 자세 및 행동 분석과 공간인지 기능을 검증하기 위하여 실제 환경 실험을 통하여 본 논문에서 제안한 시스템의 효용성과 타당성을 검토한다.

• 센서학회지
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• 제11권4호
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• pp.200-208
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• 2002

This paper represents the development of an array-type flexible tactile sensor using PVDF(polyvinylidene fluoride) film and flexible circuitry. The tactile sensor which has $8{\times}8$ taxels is made by using PVDF film and FPC(flexible printed circuit) technique. Experimental results on static and dynamic properties are obtained by applying arbitrary forces and frequencies generated by the shaker. In the static characteristics, the threshold and the linearity of the sensor are investigated. Also dynamic response of the sensor subjected to the variable frequencies is examined. The signals of a contact force to the tactile sensor are sensed and processed in the DSP system in which the signals are digitalized and filtered. Finally, the signals are integrated for taking the force profile. The processed signals of the outputs of the sensor are visualized on a personal computer, the shape and force distribution of the contacted object are obtained using two and three-dimensional image in real time. The reasonable performance for the detection of contact state is verified through the experiment.

• 센서학회지
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• 제32권5호
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• pp.295-299
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• 2023

Herein, we propose a simple fabrication method for MXene-coated V-groove sensors for applications. To enhance the sensitivity of this sensor, we applied MXene particles, instead of conventional metal layers, as a sensing material on the sensor's surface. This allows for an easier fabrication, as well as higher sensitivity of the sensor compared to those of our previously demonstrated metal-based V-groove sensor. Additionally, polyurethane-acrylate, a UV-curable liquid polymer, can be easily applied using micro-electromechanical systems-based surface-texture micromachining. The sensor sensitivity is approximately 0.08 /mm, and it can be improved by increasing the number of V-grooves. We believe that the proposed MXene-based wearable sensor offers a great potential in detecting various types of motions characteristic of human activities.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.262-267
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• 2000

This paper describes a weight in motion(WIM) sensor to measure the weight of a vehicle in motion. The main sensing element of the WIM sensor is the PVDF(Polyvinylidene fluoride) film that shows rapid response to an external excitation. Due to the property of rapid response, it is possible to measure the weight of a vehicle in motion with high speed. In the development of the WIM sensor, the dominant target value was the uniformity of the sensor. To increase the uniformity, We employed shrinkable tube made of rubber to enhance the uniformity, and performed the rolling of the brass tube repeatedly. The uniformity of the sensor was examined experimentally. It was comparable to that of a WIM sensor of the MSI which was the benchmark of this development. This paper also describes the mechanical modeling of the sensor and the suitable charge amplifier for the sensor.

• 센서학회지
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• 제29권3호
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• pp.187-193
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• 2020

Ultraviolet (UV) sensors are widely applied in industrial and military fields such as environmental monitoring, medicine and astronomy. Zinc oxide (ZnO) is considered as one of the promising materials for UV sensors because of its ease of fabrication, wide bandgap (3.37 eV) and high chemical stability. In this study, we used the hydrothermal growth of ZnO to form two types of ZnO nanostructures (Nanoflower and nanorod) and applied them to a UV sensor. To improve the performance of the UV sensor, the hydrothermal growth was used in a two-step process for fabricating ZnO hierarchical nanostructures. The fabricated ZnO hierarchical nanostructure improved the performance of the UV sensor by increasing the ratio of volume to surface area and the number of nanojunctions compared to one-step hydrothermal grown ZnO nanostructure. The UV sensor based on the ZnO hierarchical nanostructure had a maximum photocurrent of 44 ㎂, which is approximately 3 times higher than that of a single nanostructure. The UV sensor fabrication method presented in this study is simple and based on the hydrothermal solution process, which is advantageous for large-area production and mass production; this provides scope for extensive research in the field of UV sensors.