Electroresponsive Ionic Liquid Crystal Elastomers

Feng, Chenrun; Rajapaksha, Chathuranga Prageeth; Cedillo, Jesus M; Kyu, Thein; Cao, Jinwei; Kaphle, Vikash; Lüssem, Björn; Kyu, Thein; Jákli, Antal

doi:10.1002/marc.201900299

Cited by 55 publications

(62 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Very recently, the mechanical anisotropy of LCEs has been explored as dielectric elastomers where deformation is caused by directional differences in Maxwell stress 547. An LCE with ionic liquid inclusions has been shown with similar bidirectional deformation as IEAP, as described in Section 5 548…”

Section: Liquid Crystal Elastomers and Networkmentioning

confidence: 99%

Materials as Machines

2020

View full text Add to dashboard Cite

of responsive materials as machines is in robotics. The vision, leadership, and research of Bar-Cohen is seminal in both invigorating and focusing current-day research activities to develop responsive materials [2] and implement [3] them as lightweight, dexterous, and gentle (e.g., soft) robotic elements. In this spirit, this review exhaustively details the materials, the nature of their stimuli-response, and discusses considerations for their implementation in robotic systems and subsystems.Robotics is a well-established but growing field of research. Sustained progress in both performance and functionality continue to be realized in commercial robotic systems largely based on conventional materials and their integration with mechanisms. A recent example is the Atlas robot from Boston Dynamics [4] (Figure 1a). The incorporation of stimuli-responsive materials in robotics has largely focused on component-level demonstrations to extend the performance of a subsystem (such as a hand or gripper).Stimuli-responsive materials, spanning nearly all classes of materials and size scales, are currently subject to widespread examination in corporate, government, and academic research laboratories (Figure 1b-d). [5][6][7] In some cases, these materials have already found widespread commercial implementation in end use and are comparatively mature. The materials and fundamentals of their responses are summarized in Figure 2. Shape memory alloys (SMAs) and ceramic piezoelectric materials are distinctive in that they are hard, stimuli-responsive materials. Deformation of these materials can produce large energy densities due to their inherent stiffness. Electroactive polymers (EAPs) remain a topic of considerable interest, particularly dielectric elastomer actuators (DEAs). Engineered systems are rapidly emerging and enabling performance gains in robotics, largely based on pneumatic or fluidic (such as HASEL [8] actuators) transport processes that localize deformation to generate force or produce motion. Soft materials, such as shape memory polymers (SMPs), hydrogels, and liquid crystalline polymer networks (LCNs) and elastomers (LCEs) may offer distinctive functional performance to robotic systems in allowing local control of deformation without the need for complex interfacing with mechanisms. As will be evident, each of these materials has inherent advantages and performance tradeoffs that must be considered in functional implementations. However, responsive material systems have a common obstacle to widespread use: the performance and Machines are systems that harness input power to extend or advance function. Fundamentally, machines are based on the integration of materials with mechanisms to accomplish tasks-such as generating motion or lifting an object. An emerging research paradigm is the design, synthesis, and integration of responsive materials within or as machines. Herein, a particular focus is the integration of responsive materials to enable robotic (machine) functions such as gripping, lifting, or motility (walk...

show abstract

Section: Liquid Crystal Elastomers and Networkmentioning

confidence: 99%

Materials as Machines

2020

View full text Add to dashboard Cite

show abstract

“…[65][66][67] On the other hand, as soft and elasomeric materials, LCNs could also be actuated via other classical mechanisms, similar to those of dielectric elastomers and ionic electroactive polymers. [68][69][70] In particular, the programmable mechanical anisotropy of the LCNs based on their molecular alignments can be combined with these mechanisms to achieve complex shape changes. [69] Among the electrically driven systems based on LCNs, electrothermal LCNs relying on Joule heating effect can produce quick response and large deformation in dry materials with low electric current or voltage input, and thus are very promising for soft robotic applications.…”

Section: Electro-responsive Lcnsmentioning

confidence: 99%

Liquid Crystal Polymer‐Based Soft Robots

Xiao

Jiang

Zhao

2020

Advanced Intelligent Systems

View full text Add to dashboard Cite

Soft robots outperform the conventional robots on enhanced safety for human-machine interaction, environmental adaptability, and continuous deformation. In this blooming area of fundamental and technological importance, liquid crystal polymer networks and liquid crystal elastomers (referred to as LCNs) have emerged as one of the most valuable candidates for soft robots due to their complex, large, and reversible shape change capabilities. To date, much research effort, mainly regarding chemical synthesis, fabrication technologies and soft robot design, has been dedicated to LCN robotic systems to endow them with versatile and complex actions controlled by various stimuli. Herein, starting with the principle that governs the stimuli-responsiveness of LCNs, recent progress made in LCN soft robots is summarized while focusing on different robotic motions, such as grapping, walking, swimming, and oscillation. Especially, novel LCNs with intelligent functions such as reprocessability, reconfigurability, self-regulating behavior and associative learning capability, are highlighted. This article aims to provide significant insights into the design and development of LCN-based soft robots.

show abstract

“…The flexoionic effect was studied using thick carbon based electrodes, which increase the bending modulus of the actuators. However, recently, we got experience with 1–2µm thick PEDOT:PSS electrode coating studying ionic liquid crystal elastomers 44. For this reason, we studied voltage induced flexing (converse flexoelectric) effects of the PEGDA/TS/IL system (see Figure 1b) sandwiched between PEDOT:PSS 45.…”

Section: Figurementioning

confidence: 99%

“…Using the displacement value measured at 1 V, we find Y a ≈ 15 MPa, which is about three times larger than that measured on the plain film without electrodes Yp = 5.1MPa (see Figure S1, Supporting Information), showing the added stiffness by the PEDOT:PSS layers. Using the measured Y P and the Young's modulus of the PEDOT:PSS electrode, Y e ≈ 1 GPa, thickness of the polymer film d = 0.2 mm and of the electrode h ≈ 2 µm (as measured by optical microscope),44 the Young's modulus of the film with electrodes Y a = 15.32 MPa was calculated from the equations given by Stafford et al48 (see Supporting Information), representing good agreement with the measured value.…”

Section: Figurementioning

confidence: 99%

“…This work demonstrated a high‐performance soft actuator based on PEGDA and TS with PEDOT:PSS electrodes. This is illustrated by comparing 1 V induced 0.38% strain for our system with results reported in recent review article by Park et al5 In Figure S2, Supporting Information, we compare the TS/PEGDA/IL/PEDOT:PSS system with other iEAPs such as poly(styerenesulphonate‐b‐methylbutylene) (P17(PSS‐b‐PMB)(75));4 polyether‐segmented polyurethaneurea;19 PS‐PMMA‐PS:49 Graphene‐Nafion composite;40 Nafion;40 poly(styerenesulphonate‐b‐methylbutylene) (PSS‐b‐PMB/ZImS);6 ionic gel/metal nano‐composite;27 sulfonated polybenzimiduzole42 and Ionic liquid crystal elastomer,44 and find that our system has the second best performance after PSS‐b‐PMB (sulfonated block copolymer) which has a strain of 0.47% at 1 V.…”

Section: Figurementioning

confidence: 99%

See 1 more Smart Citation

Poly(ethylene glycol) Diacrylate Based Electro‐Active Ionic Elastomer

Rajapaksha

Feng

Kyu

et al. 2020

Macromol. Rapid Commun.

Self Cite

View full text Add to dashboard Cite

Preparation and low voltage induced bending (converse flexoelectricity) of crosslinked poly(ethylene glycol) diacrylate (PEGDA), modified with thiosiloxane (TS) and ionic liquid (1‐hexyl‐3‐methylimidazolium hexafluorophosphate) (IL) are reported. In between 2µm PEDOT:PSS electrodes at 1 V, it provides durable (95% retention under 5000 cycles) and relatively fast (2 s switching time) actuation with the second largest strain observed so far in ionic electro‐active polymers (iEAPs). In between 40 nm gold electrodes under 8 V DC voltage, the film can be completely curled up (270° bending angle) with 6% strain that, to the best of the knowledge, is unpreceded among iEAPs. These results render great potential for the TS/PEGDA/IL based electro‐active actuators for soft robotic applications.

show abstract

Electroresponsive Ionic Liquid Crystal Elastomers

Cited by 55 publications

References 49 publications

Materials as Machines

Materials as Machines

Liquid Crystal Polymer‐Based Soft Robots

Poly(ethylene glycol) Diacrylate Based Electro‐Active Ionic Elastomer

Contact Info

Product

Resources

About