Large actuation and high dielectric strength in metallized dielectric elastomer actuators

Abstract

Metal films are seldom used as compliant electrodes for dielectric elastomer actuator (DEA) because they tend to restrain deformation of soft dielectrics. This work showed that silver film electrodes formed by electroless deposition (ELD) are indeed stretchable, and the DEA using ELD silver electrodes is able to generate an actuation up to 50% areal strain. Such ELD silver electrodes can self-heal, remain conductive at up to 33% uni-axial strain, and do not stiffen the dielectric layer as much as the sputtered silver electrodes. This metallized DEA can sustain a high breakdown field up to 350 MV/m, which is good for generating a large actuation force.

Dielectric elastomer actuators based on stretchable and self-healable hydrogel electrodes

“…Carbon grease is widely used [17,24], a highest areal strain of 1692% has been reported by Suo's group [25,26]. CNTs [15], graphite powder [13] and corrugated metal [21,22] directly deposited on the dielectric polymer are able to generate large actuation strains, but it is found that these materials have poor mechanical adhesion with DEAs, and are not applicable for miniaturization [14,27]. Stretchable composite materials prepared by incorporation of CNTs, nanowires or graphene into elastomer are alternative electrodes for the DEAs.…”

“…Compliant electrode is an important component for DEAs, since they must be able to synchronously follow large strains of the elastomer without generating an opposing stress or losing conductivity [13]. Therefore, properties such as large stretchability and high electrical conductivity are highly demanded for compliant electrodes [14][15][16][17][18][19][20][21][22][23]. A variety of materials including carbon grease [13], carbon nanotubes (CNTs) [15], nanowires [14] and graphene [16] have been investigated as the electrodes for DEAs up to now.…”

Numerical characterization of local electrical breakdown in sub-micrometer metallized film capacitors

“…With increasing applied voltage, the film at this point will discharge first, forming a discharge channel. Because the high pressure air has a much lower electrical strength than the dielectric polymer film, and the air gap will withstand the high electric field strength during the charging of the capacitor, the breakdown and failure will most likely occur first in the air gaps [4,5]. The charged particles produced by the air discharge will bombard the dielectric film and sometimes produce a breakdown in it, and finally self-healing will occur.…”

“…It is clear that understanding this discharging process is crucial to select the criterion that really controls the self-healing process and thus to improve the performance of MFCs. In fact, although many experimental efforts have been performed to study this process [1][2][3][4], no numerical simulations have been performed to investigate it up till now.…”

Synergistic effect of self-assembled carbon nanopaper and multi-layered interface on shape memory nanocomposite for high speed electrical actuation

“…Stimuli-responsive polymers are one of the many types of smart materials that could show noticeable changes in their properties continuously with the environmental conditions. 1,2 These responsive polymers can adapt to surrounding environments, in a number of ways including like altering colour or transparency, changing shape (shape memory polymers, SMPs), or converting electrical signals into optical, chemical, thermal and mechanical signals, and vice versa. [3][4][5][6] SMPs are able to change their shape or other chemical/physical properties in the presence of a particular stimulus.…”