This demo presents the Electrostatic Bellow Muscle (EBM), a flexible multipurpose
actuator that is obtained by stacking multiple bellow-shaped actuation units. EBM takes
inspiration from previous work on liquid-gap electrostatic actuators introducing a new
architecture. This novel solution makes it possible to implement an actuator that features a
flexible/multipurpose applications such as contractile muscle, pump or energy harvester, while
maintaining performance that are comparable to those of previously developed actuation
systems. Additionally, a very simple manufacturing process makes it possible to scale up force
or displacement by arranging in series or in-parallel actuators.
Specifically, the demo will show an EBM with cylindrical shape with a
diameter of 30 mm and a height sof 14 mm lifting a weight of approximately 300g with a
displacement of 6-7mm at different frequencies.
Actuators driven by electrostatic force represent a very promising opportunity for the development of advanced robotic systems. Dielectric elastomer actuators have been long investigated and more recently devices based on fluid dielectric have been proposed as a possible alternative that shows remarkable performance.
Here, we present a novel electrostatic actuator that is made of thin polyimide films and liquid dielectric, combined with rigid plates assembled to form a circular actuation unit that undergoes to out-of-plane expansion/contraction. Prototypes of these actuation units have been tested showing a contraction of up to 40%, a maximum power density during contraction of 100 W/kg, a maximum strain rate of 1000% per second, a bandwidth of approximately 10 Hz, and the ability to lift hundreds of times their weight.
Additionally, these units resulted easy to manufacture in different dimensions and can be assembled in arrays and stacks to form an electrostatic bellow muscles (EBM) that can be effectively employed as a contractile artificial muscle, as pump and as electrostatic generator. EBM demonstrated their flexibility in matching a wide range of requirements and scales in terms force-displacement combinations and bandwidth.
The compact 2-D shape, the low-cost of components, the simple assembling procedure, the high level of reliability and the relevant performance make the EBM a possible enabling technology for a variety of high-performance robotic and mechatronic systems.
Recent research work has shown that dielectric fluids, with specific properties, can be combined with stretchable or flexible shell structures, made of polymeric dielectric/electrode composite films, to implement a novel type of soft electrically-driven fluidic transducers with self-healing and self-sensing capabilities that take the name of Liquid based Electro-Active Polymer transducers (LEAPs). These devices are similar to dielectric elastomer transducers in regards to their electrostatic working principle, but they can potentially produce larger displacements due to their lower mechanical stiffness. In this contribution, we present a new transducer concept in which LEAP actuators are employed to induce out-ofplane deformation of a membrane. Specifically, experimental and theoretical demonstrations are provided for applications as dot actuator for Braille displays or other tactile feedback implementations. Results obtained on a preliminary prototype show that the system is able to provide a perceivable force for a human fingertip, offering potential room for further improvement and optimization. Electrically-induced cyclic actuation can be produced over a wide range of frequencies. The results presented in this paper prove the applicability of the LEAP principle on tactile devices and show new design paradigms for this technology.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.