Tactile information is prerequisite for dexterous manipulation of objects with robots. In this paper a novel tactile sensor using dielectric elastomer is presented. The sensor is a capacitive type and it can be easily covered onto any curved surface due to the intrinsic flexibility of the dielectric elastomer. The practical design and fabrication of a tactile sensor for the robot fingertip are described in details in this paper. Also,a fingertip shaped tactile sensor with twelve tactile cells is developed. The sensor is mounted on a multi-fingered robot hand, called "SKKU Hand III", and its effectiveness is validated with experimental results.
Previously, the dielectric elastomer based on Acrylonitrile Butadiene Rubber (NBR), called synthetic elastomer
has been reported by our group. It has the advantages that its characteristics can be modified according to
the requirements of performances, and thus, it is applicable to a wide variety of applications. In this paper, we
address the effects of additives and vulcanization conditions on the overall performance of synthetic elastomer.
In the present work, factors to have effects on the performances are extracted, e.g additives such as dioctyl
phthalate (DOP), barium titanium dioxide (BaTiO<sub>3</sub>) and vulcanization conditions such as dicumyl peroxide
(DCP), cross-linking times. Also, it is described how the performances can be optimized by using DOE (Design
of Experiments) technique and experimental results are analyzed by ANOVA (Analysis of variance).
In this paper, we present a new haptic interface, called "active skin", which is configured with a tactile sensor
and a tactile stimulator in single haptic cell, and multiple haptic cells are embedded in a dielectric elastomer.
The active skin generates a wide variety of haptic feel in response to the touch by synchronizing the sensor and
the stimulator. In this paper, the design of the haptic cell is derived via iterative analysis and design procedures.
A fabrication method dedicated to the proposed device is investigated and a controller to drive multiple haptic
cells is developed. In addition, several experiments are performed to evaluate the performance of the active skin.
As a major human sensory function, the implementation of the tactile sensation for the human-machine interface
has been one of the core research interests for long time. In this research, tactile display devices based on
dielectric elastomer are introduced among the works recently done by ourselves. Using dielectric elastomer for
the construction of the tactile interface, it can provide stimulation on the human skin without any additional
electromechanical transmission. Softness and flexibility of the device structure, ease of fabrication, possibility for
miniaturization, and cost effectiveness are the representative benefits of the presented devices. Especially, the
device application is open to a wide variety of purposes since the flexible structure offers excellent adaptability
to any contour of the human body as well as the other objects. In this paper, the design of the interfaces is
briefly explained and several examples of implementation are introduced.
The objective of the present work is to demonstrate the efficiency and feasibility of NBR (Nitrile Butadiene Rubber)
based conducting polymer actuator that is fabricated into a micro zoon lens driver. Unlike the traditional conducting
polymer that normally operates in a liquid, the proposed actuator successfully provides fairly effective driving
performance for the zoom lens system in a dry environment. And this paper is including the experiment results for an
efficiency improvement. The result suggested by an experiment was efficient in micro optical zoom lens system. In
addition, the developed design method of actuator was given consideration to design the system.
In this paper we present a dielectric elastomer actuator, which has the ability to sense the force acting on it
without any additional sensing device. Basic physical behaviors of the dielectric elastomer are experimentally
investigated and it is noted that the impedance of the dielectric elastomer varies depending on external forces
acting on it. Based on that concept, we propose the principle of a self-sensing actuator according to experimental
result. In addition, a multi-stacked actuator with self-sensing capability is realized to validate its feasibility.
Normally, various micro-scale devices adopt electromechanical actuators for their basic mechanical functions.
Those types of actuators require a complicated power transfer system even for generating a tiny scale motion.
Since the mechanical power transfer system for the micro-scale motion may require many components, the
system design to fit those components into a small space is always challenging. Micro-optical zoom lens systems
are recently popularly used for many portable IT devices such as digital cameras, camcorder, and cell phones,
Noting the advantages of EAP actuators over the conventional electromechanical counterparts in terms of simple
actuator mechanisms, a micro-optic device that is driven with the EAP actuator is introduced in the present
work. EAP material selection, device design and fabrication will be also delineated.
In this paper we present a new artificial muscle actuator for rectilinear motion made of synthetic elastomer,
which is mainly focused on the robotic applications. Previously, we have developed a new material for actuating
means, named "synthetic elastomer". Synthetic elastomer allows their material properties such as mechanical as
well as electrical properties to be adjusted according to the requirements. Using the synthetic elastomers made
of the recipe adjusted for the robotic application, a new design of the artificial muscle actuator, called multi
stacked actuator is proposed. The actuator is comprised of multiple stacks of synthetic elastomer coated with
compliant electrodes and connecting disks. This unique design enables its linear actuation with the large strain
of active length as well as large force. Experimental works are conducted and the effectiveness of the actuator is
This paper presents a new artificial muscle actuator produced from
dielectric elastomer, called Tube-Spring Actuator(TSA). The new
actuator construction includes two steps: the first part is a
cylindrical actuator manufactured with dielectric elastomer and
the second is a compressed spring inserted inside the tube. An
inner spring is used to maximize the axial deformation while
constraining the radial one. This unique design enables linear
actuation with the largest strain of active length up to 14%
without any additional means. As a result this actuator was
applied to a robot hand. This study lays the foundation for the
future work on dielectric polymer actuator.
Among ElectroActive Polymers (EAPs) the dielectric elastomer actuator
is regarded as one of the most practically applicable in the near
future. So far, its effect on the actuation phenomena has not been discussed sufficiently, although its strong dependency on prestrain is a significant drawback as an actuator. Recent observations clarifies that prestrain has the following pros and cons: prestrain plays an important role in generating large strain, whereas it rather contributes to the reduction of the strain. Prestrain provides the advantages of improving the response speed, increase of the breakdown voltage, and removing the boundary constraint caused by the inactive actuation area of the actuator. On the contrary, the elastic forces by prestrain makes the deformation smaller and the induced stress relaxation is severely detrimental as an actuator. Also, the permittivity decreases as prestrain goes up, which adds an adverse effect because the strain is proportional to the permittivity. In the present work, a comprehensive study on the effects of prestrain is performed. The key parameters affecting the overall performances are extracted and it is experimentally validated how they work on the actuation performance.