• The Journal of Korea Robotics Society
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• v.8 no.3
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• pp.150-155
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• 2013

Vibrotactile actuators for small consumer electronic products, such as mobile devices, have been widely used for conveying haptic sensation to users. One of the most important things in vibrotactile actuators is to be developed in the form of thin actuator which can be easily embedded into mobile devices and to provide vibrotactile signals with wide frequency band to users. Thus, this paper proposes a thin film type haptic actuator with an aim to convey vibrotactile information with high frequency bandwidth to users in mobile devices. To this end, a vibrotactile actuator which creates haptic sensation is designed and constructed based on cellulose acetate material. A cellulose acetate material charged with an electric potential can generate vibration under the AC voltage input. It is found that the motion of the actuator can have concave or convex shape by controlling a polarity of both charged membranes and the actuator performance can be modulated by increasing level of biased electric potential. The experiment clearly shows that the proposed actuator creates enough output force to stimulate human skin with a large frequency bandwidth and to simulate various vibrotactile sensations to users.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.8
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• pp.795-800
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• 2014

In this paper, a vibrotactile pad system, T-mobile, is developed to provide vibrotactile cues for hand-held devices. A grooved and slim design is adapted to the back-side plane of the T-mobile, and the contact part consists of 12 vibrotactile panels which can operate independently and separately. To be isolated among vibrotactile actuators, the surface of the cover is divided into several pieces. Each vibrating module consists of a linear resonant actuator, a section of covering surface, and a vibration isolator. In order to provide spatial and directional information, sensory saltation and phantom sensation are applied to the T-mobile. To evaluate the developed device, two experiments were conducted to test whether directional information and spatial information can be successfully displayed by the device. Additionally, in order to find optimal stimulation by sensory saltation, an empirical test was conducted. As a result, spatial and directional information would be useful for displaying intuitive information for hand-held devices with vibrotactile feedback and reasonable near-optimal value for sensory saltation was obtained.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.11
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• pp.1259-1264
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• 2011

This paper suggests a new film-type haptic actuator based on cellulose acetate electro-active paper. Conventional tiny haptic actuators in mobile devices can create vibrotactile sensation at only near resonant frequency. The strategy of operating near the resonant frequency, however, brought a new issue for creating vibrotactile sensation which can be strong enough to feel in arbitrary frequency. Another problem is that the size of the conventional actuator is not small enough to be embedded into slim mobile devices. In order to achieve these issues, we propose a thin and tiny actuator based on a cellulose acetate material charged with an electric potential. The motion of the actuator can be a concave or a convex by controlling a polarity of both charged membranes and the actuator performance can be modulated by increasing level of biased electric potential.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.1683-1687
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• 2009

This paper addresses a haptic actuator which can be applied to mobile devices. For haptic feedback in mobile devices, we have to consider not only stimulating force and frequency but also the size and the power consumption of a haptic module. Thus far, vibration motors have been widely used in mobile devices to provide tactile sensation. The reason is that a vibration motor is small enough to be inserted into a mobile device. This paper addresses vibrotactile actuators and other haptic actuators which can generate a wide variety of tactile sensations.

• Smart Media Journal
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• v.1 no.4
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• pp.8-17
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• 2012

In this paper, we introduce the appoaches that aim to improve user experience in mobile device by the use of multiple vibration signal feedback, conducted by Haptics and Virtual Reality laboratory at POSTECH. We introduce current progresses of our 'Vibrotactile flow using multiple vibration actuators' and 'Real-time dual-channel haptic music player.' The 'Vibrotactile flow using multiple vibration actuators' produces vibrotactile flow sensations by using multiple actuators and that improves the information transfer on mobile devices. The 'Real-time dual-channel haptic music player' generates vibrotactile sensation by transforming auditory signal, which improves the user experience of mobile devices. These approaches can be good examples to fulfill the demands of better information transfer capability and user experience on mobile devices.

• Journal of Korea Multimedia Society
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• v.14 no.9
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• pp.1210-1220
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• 2011

In this paper, we suggest a haptic mouse system as an immersive interface between virtual environment and a human operator. The proposed haptic mouse creates vibrotacitle and thermal sensation to increase the immersion. The vibrotactile module is composed of eccentric motors and a solenoid actuator, and the thermal module consists of a thin-film resistance temperature detector and a Peltier thermoelectric heat pump. In order to evaluate the proposed haptic mouse system, we develop a simple racing game and conduct an experiment. The result of the experiment shows that the proposed haptic mouse system can improve the sense of reality in virtual environment and can be used as an effective interface between virtual environment and a human operator.

• Journal of Digital Contents Society
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• v.18 no.7
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• pp.1435-1441
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• 2017

The primary goals of this paper are to design an interactive education platform conveying a variety of haptic sensations to developmental disorder children when they touch the education platform. The proposed interactive education platform is composed of a kinesthetic module, a vibrotactile module, a thermal module. and a controller. The design focuses of the proposed education platform were to create sufficiently large kinesthetic forces, vibrations, and temperatures and to convey them to users. We have conducted experiments for evaluating the proposed system and found out three modules function safely and effectively as an educational platform.

• Journal of the Ergonomics Society of Korea
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• v.32 no.4
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• pp.355-361
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• 2013

Objective: The aim of this study is to investigate the gender-differences in vibrotactile responses(sensitivity and displeasure) of residual forearm simulated by vibration stimulation in upper limb(trans-radial) amputees. Background: Several studies have reported that vibration stimulation using the haptic vibrator is one the most effective methods for delivering sensation to an amputees. However, few studies have reported the perception to haptic vibratory stimulus, particularly sensitivity and displeasure. Method: We set up a custom-made vibration stimulation system that included 6 actuators(3 medial parts and 3 lateral parts) and a graphical user interface(GUI)-based acquisition system to investigate changes in residual somatosensory sensibility and displeasure in the forearm of upper limb(trans-radial) amputees. Vibration actuators were attached at the 25%-point on the proximal forearm. Stimulation with 32Hz, 64Hz, or 149Hz of frequency was used for the sensitivity tests and with 32~257Hz of frequency was used for the discomfort experiments. The subjective responses were evaluated on a 10 point scale. Results: The results showed that vibrotactile sensory perception in male amputees were higher than that in female amputees. In male amputees, the response at lateral area of forearm was the most sensitive than medial area; but, female amputees showed similar sensitive areas. Subjects did not experience any discomfort during vibrotactile stimuli. Conclusion: Vibrotactile response in the amputees was dependent on gender as well as area stimulated by vibration. Application: The results might contribute to develop the vibrotactile feedback system for the amputees.

• Journal of Internet Computing and Services
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• v.24 no.6
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• pp.23-29
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• 2023

As an effort to maximize the immersiveness of user experience in virtual reality, there have been constant efforts to provide a user with tactile sensation by providing haptic feedback. Most of the haptic feedback methods, however, can create only limited or unrealistic haptic sensations since they utilize affordable actuators such as a vibrotactile actuator. When it comes to martial arts training or a game, the limitation of such haptic feedback is apparent due to the significant difference between the physical impact of hitting an object and the sensation departed from a vibrotactile actuator. Noting this, we proposed a haptic impact system that can create a haptic impact when the user hits a virtual object with the fist. The haptic interface uses a quick-return mechanism that can deliver haptic impact feedback to a user's fist. The realism of the haptic impact was evaluated by conducting a human-subject experiment. The results indicate a significant effect of haptic feedback on the realism of the virtual impact.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.230-237
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• 2006

본 논문은 스포츠 방송의 몰입감 증대를 위한 진동촉감 제시 시스템 및 장치를 제안하며, 촉감 정보를 효과적으로 전달하기 위한 촉감제시 방법론 및 제어 알고리즘을 제안한다. 최근 디지털 컨텐츠의 전달에 있어 오감을 통한 정보 전달의 관심이 증대됨에 따라, 대중을 대상으로 다양한 정보를 전달하는 디지털 매체에서의 시청각과 더불어 촉감 제시의 역할과 중요성이 증대되었다. 따라서 본 논문에서는 실시간으로 동적인 현장 상황을 실감 있게 전달하는 스포츠 방송에서의 햅틱 효과와 역할 그리고 가능한 시나리오를 정의하고, 진동촉감 제시 장비를 설계하여 촉감 정보 표현에 대한 기초 연구를 수행하였다. 또한 제안된 촉감을 이용한 스포츠 방송 시나리오 중 축구 방송을 기반으로 사용자 촉감 인지 실험을 수행하였으며, 실험 결과를 바탕으로 축구 방송 시스템을 구축하여 실감방송 전시회 시연을 통해 진동촉감 시스템 및 촉감 제시 방법론을 검증하였다. 촉감이 인간의 오감 중 시청각 다음으로 정보를 인지하는 중요한 감각 체계인 만큼 많은 양의 정보를 대중에게 전달하는 방송 시스템에서 시청각과 더불어 효과적인 정보 전달 체계로써 기여할 것이라고 여겨진다.