Multiresponsive Actuators Research Articles

An optimized complementary design based on trilayer graphene oxide and clay composites for three stimuli responsive actuator

To promote the practical development of actuators, it is urgent to develop new multi-responsive actuators. Asymmetric bilayer actuators were reported to be dual-responsive, which can be driven by humidity and light. However, it remains a great challenge to develop rational designs for fabricating high-performance multi-responsive actuators. Here, we propose an optimized complementary design for three stimuli responsive actuators that can respond to multiple organic vapors, humidity, and light. The actuator is designed to achieve complementarity through a trilayer construction with graphene oxide (GO) in the middle layer, and with montmorillonite (MMT) and biaxially-oriented polypropylene (BOPP) on both sides, utilizing their hygroscopicity, organic vapor absorption, light absorption and thermal expansion capabilities. The maximum bending curvatures of the actuator under humidity, organic vapor and light stimulation conditions are 6.60 cm-1, 4.12 cm-1 and 2.59 cm-1 respectively, which are better than that of mixed GO-MMT/BOPP bilayer actuators. To reveal the kinetics of actuation, the actuation speed, temperature and mass during the deformation process are studied, which behave in sync with the bending curvature. Finally, a wireless intelligent claw and an organic-vapor leakage alarm are demonstrated based on these actuators. This study will provide an enlightening reference for multi-responsive actuators and promote their practical development.

A multi-responsive actuator with sensing capability based on poly (N-isopropyl acrylamide)/poly (sodium acrylate) Janus hydrogels

A Janus hydrogel composed of temperature-responsive poly (N-isopropyl acrylamide) (PNIPAM) and pH-responsive poly (sodium acrylate) (PSA) was fabricated from inexpensive monomers using a facile synthesis route. The asymmetric swelling between PNIPAM and PSA in different media and at different temperatures makes the Janus hydrogels have a multi-stimuli response, meanwhile, the interpenetrating layer between PNIPAM and PSA indicated a good interfacial adhesion for easy transfer of internal stress and deformation. Thus, the Janus hydrogels exhibited excellent advantages in actuator/sensor engineering, demonstrating the potential to grip and release objects in toxic media, encrypt, monitor and control safety in chemical production, and alert temperature of flammable and explosive solvents. In addition, the features of the Janus hydrogels incorporated with carbon nanotubes, such as the high sensitivity, large stretchability, and rapid and linear response, enabled their application as strain sensors for wearable technologies in the recognition of body movement and health detection.

Quantum-Confined-Superfluidics-Enabled Multiresponsive MXene-Based Actuators.

MXene, renowned for its natural "quantum-confined-superfluidic" (QSF) channels, demonstrates superior electrical/thermal conductivity, favorable hydrophilicity, and remarkable mechanical strength, rendering it an ideal candidate for multiresponsive actuators, which are promising for soft electronics and robots. Currently, most MXene-based actuators are mainly prepared by combining an active layer and an inner layer, with only a few utilizing regulated QSF channels. However, tailoring QSF channels for multiresponsive actuators is extremely challenging. Herein, we introduce a multiresponsive graphene oxide (GO)&Fe3O4/MXene actuator that can respond to humidity, light, heat, electricity, and magnetic fields by constructing asymmetric QSF channels. The asymmetric water adsorption, transportation, and desorption behaviors, controlled by the different QSF channels between the GO&Fe3O4 layer and the MXene layer, enable the multiresponsiveness of the actuator. As proof-of-concept demonstrations, several smart devices, such as a bionic crab-like crawler, a transporting flower robot, and a smart gripper, are prepared, holding great potential for advancing future soft robotics.

Enable Multi-Stimuli-Responsive Biomimetic Actuation with Asymmetric Design of Graphene-Conjugated Conductive Polymer Gradient Film.

In this paper, multiresponsive actuators based on asymmetric design of graphene-conjugated poly(3,4-ethylene dioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) gradient films have been developed by a simple drop casting method. The biomimetic actuation is attributed to the hygroscopic expansion property of PEDOT:PSS and the gradient distribution of graphene sheets within the film, which resembles the hierarchical swelling tissues of some plants in nature. Graphene-conjugated PEDOT:PSS (GCP) actuators exhibit reversible bending behavior under multistimuli such as moisture, organic vapor, electrothermal, and photothermal heating. Noticeably, the bending curvature reaches 2.15 cm-1 under applied voltage as low as 1.5 V owing to the high electrical conductivity of GCP actuator. To mimic the motions of nyctinastic plants, a GCP artificial flower that spreads its petals under sunlight illumination has been fabricated. GCP actuators have been also demonstrated as intelligent light-controlled switches for light-emitting diodes and smart curtains for thermal management. Not only do the GCP gradient films exhibit potential applications in flexible electronics and energy harvesting/storage devices but also the facile fabrication of multiresponsive GCP actuators may shed light on the development of soft robotics, artificial muscles, wearable electronics, and smart sensors.

Liquid Metal-Promoted Graphene Oxide Supramolecular Film for Self-Healing Actuator with Multiple-Stimuli Responses.

The structural vulnerability and immobility of the multi-responsive actuators restrict its application in soft robots. Hence, self-healing film actuators based on interfacial supramolecular crosslinking and hierarchical structural design have been developed. The graphene oxide supramolecular film with asymmetric structure reveals excellent reversible deformation under different trigger signals like moisture, thermal, and infrared light. Meanwhile, it shows a good healing property based on supramolecular interaction, achieving the structure restoration and reconstitution of stimuli-responsive actuators (SRA). The re-edited SRA realizes reverse reversible deformation under the same external stimuli. To enhance the functionality of graphene oxide-based SRA, the reconfigurable liquid metal could be modified on the surface of the graphene oxide supramolecular film at low temperature (defined as LM-GO) due to its compatibility for hydroxyl. The fabricated LM-GO film displays satisfactory healing property and good conductivity. Besides, the self-healing film maintains strong mechanical strength, which can bear more than 20 grams of weight. This study provides a novel strategy to fabricate self-healing actuator with multiple responses, accomplishing the functional integration of the SRAs.

Multifunctional superhydrophobic coatings for controllable self-propelled motion

Recently, multi-responsive actuators have attracted great attention, and it remains challenging to develop flexible and durable actuators with controllable motions on water surface. Here, a facile spray-coating method is proposed to fabricate superhydrophobic and multi-responsive acidified carbon nanotubes /Fe3O4/octadecylamine/polydimethylsiloxane (CFOP) coatings. The CFOP coating imparts the paper composite (CFOP@paper) with superhydrophobicity, self-cleaning performance, excellent photothermal conversion and magnetic properties. In addition, the strong interfacial adhesion between the coating and the paper ensures the surface stability and durability during cyclic bending and abrasion tests. The CFOP@paper can achieve controllable light-driven motion based on the Marangoni effect. The CFOP coating is also used for preparation of the superhydrophobic/superoleophilic sponge composite, and the controllable and fast motions of the sponge composite are realized by a contactless magnetic field, which can be used for high efficiency adsorption of oil on water surface. The multi-responsive coating exhibits promising applications in the field of flexible electronics, smart actuators, environmental protection, and so on.

Scalable functionalized liquid crystal elastomer fiber soft actuators with multi-stimulus responses and photoelectric conversion.

Liquid crystal elastomer (LCE) fibers exhibit large deformation and reversibility, making them an ideal candidate for soft actuators. It is still challenging to develop a scalable strategy and endow fiber actuators with photoelectric functions to achieve tailorable photo-electro-thermal responsiveness and rapid large actuation deformation. Herein, we fabricated a multiresponsive actuator that consists of LCE long fibers obtained by continuous dry spinning and further coated it with polydopamine (PDA)-modified MXene ink. The designed PDA@MXene-integrated LCE fiber is used for shape-deformable and multi-trigger actuators that can be photo- and electro-thermally actuated. The proposed LCE fiber actuator combines an excellent photothermal and long-term electrically conductive PDA@MXene and a shape-morphing LCE fiber, enabling their robust mechanical flexibility, multiple fast responses (∼0.4 s), and stable and large actuation deformation (∼60%). As a proof-of-concept, we present near-infrared light-driven artificial muscle that can lift 1000 times the weight and an intelligent circuit switch with stable controllability and fast responsiveness (∼0.1 s). Importantly, an adaptive smart window system that integrates light-driven energy harvesting/conversion functions is ingeniously constructed by the integration of a propellable curtain woven by the designed fiber and solar cells. This work can provide insights into the development of advanced intelligent materials toward soft robotics, sustainable energy savings and beyond.

Multi-functional and integrated actuators made with bio-inspired cobweb carbon nanotube–Polymer composites

Soft actuators have emerged as flexible platforms that can integrate many functional electronic devices to build intelligent electronic systems. The energy supply and wireless signal transmission of electronic systems of the multi-functional actuators are challenging research areas. Here, the idea of the functionalized and hierarchical design is proposed to construct the multi-functional and integrated actuators. Inspired by the structure of cobwebs, multi-functional carbon nanotube (CNT)-polymer composites with network structures are proposed and applied in multi-responsive actuators, supercapacitors, and electromagnetic interference (EMI) shielding devices. Two multi-functional and integrated actuators are highlighted to demonstrate the practical applications. One is a light-driven actuator integrated with an EMI shielding function, which can be used as an intelligent shielding curtain. The other is an electrical-driven actuator integrated with an energy storage function. Especially, the functions of actuation and energy storage can be simultaneously/independently used without interfering with each other. We provide comprehensive research from the material level (CNT-polymer composites) to the device level (actuators, supercapacitors, EMI shielding devices), and then to the system level (multi-functional actuators). We believe that the integration design of the multi-functional actuators will open up new avenues for the development of soft robotics, wireless signal transmission switch, and deformable supercapacitors.

Recent progress in PNIPAM-based multi-responsive actuators: A mini-review

• The preparation methods of PNIPAM-based hydrogel actuators are summarized. • Different response types of PNIPAM-based hydrogel are reviewed. • A broad range of engineering applications are presented. • It is expected to prepare hydrogel actuators with more advanced properties. Hydrogels are water-absorbing materials with three-dimensional network structures. Hydrogel actuators have heterogeneous structures and can respond to specific environmental stimuli. As a typical temperature-responsive polymer, Poly(N-isopropylacrylamide) (PNIPAM) can be combined with other environmental responsive materials to design and manufacture actuators responsive to multiple environmental stimuli. As an emerging material, PNIPAM-based multi-responsive soft actuators could be used in soft robotics, tissue engineering, bionics, and other fields. This review comprehensively introduces the construction methods of the PNIPAM-based hydrogel actuators. Based on the types of environmental response, the designs and applications of the environmental stimuli-responsive hydrogel actuators based on PNIPAM are discussed. In addition, conclusions and perspectives are presented to indicate some issues and expectations for the future studies.

Dual‐responsive and bidirectional bending actuators based on a graphene oxide composite for bionic soft robotics

AbstractIntelligent actuators have become a research hotspot in smart materials in recent years due to their diverse modes of actuation, various types of deformation, and wide range of applications. However, the application fields of the traditional bilayer actuator that can only be driven by a single stimulus are greatly limited. Hence, it is necessary to develop multiresponsive actuators to broaden the application fields of the actuators. Here, we propose dual‐responsive and bidirectional bending actuators based on a composite of graphene oxide (GO) and polyethylene terephthalate (PET). The actuator is made by vacuum filtration of GO film and hot‐press of PET film. Due to the hygroexpansion effect, the GO/PET actuator can be driven by humidity. Benefitting from the ability of the light‐to‐thermal conversion and the difference in the coefficient of thermal expansion between the GO and PET, the GO/PET actuator can be driven by light. Moreover, three types of demo models (including bionic flower, smart gripper, and bionic worm robot) based on the actuator have been proposed to verify the potential of the actuator in practical applications. These demo models show that the actuators have great potential to be used in the fields of intelligent robots.

Charged Block Copolymers: From Fundamentals to Electromechanical Applications.

Charged block copolymers are promising materials for next-generation battery technologies and soft electronics. Although once it was only possible to prepare randomly organized structures, nowadays, well-ordered charged block copolymers can be prepared. In addition, theoretical and experimental analyses of the thermodynamic properties of charged polymers have provided insights into how to control nanostructures via electrostatic interactions and improve the ionic conductivity without compromising mechanical strength, which is crucial for practical applications. In this Account, we discuss methods to control the self-assembly and ion diffusion behavior of charged block copolymers by varying the type of tethered ionic moieties, local concentration of embedded ions with controlled electrostatic interactions, and nanoscale morphology. We discuss with particular emphasis on the structure-transport relationship of charged block copolymers using various ionic additives to control the phase behavior electrostatically as well as the ion transport properties. Through this, we establish the role of interconnected ionic channels in promoting ion-conduction and the importance of developing three-dimensional interconnected morphologies such as gyroid, orthorhombic Fddd (O70) networks, body-centered cubic (bcc), face-centered cubic (fcc), and A15 structures with well-defined interfaces in creating less tortuous ion-conduction pathways. Our prolonged surge and synthetic advances are pushing the frontiers of charged block copolymers to have virtually homogeneous ionic domains with suppressed ion agglomeration via the nanoconfinement of closely bound ionic moieties, resulting in efficient ion conduction and high mechanical strength.Subsequently, we discuss how, by using zwitterions, we have radically improved the ionic conductivity of single-ion conducting polymers, which have potential for use in next-generation electrochemical devices owing to the constrained anion depletion. Key to the improvement stems from hierarchically ordered ionic crystals in nanodomains of the single-ion block copolymers through the self-organization of the dipolar/ionic moieties under confinement. By precisely tuning the distances between ionic sites and the dipolar orientation in the ionic domains with varied zwitterion contents, unprecedented dielectric constants close to those of aqueous electrolytes have been achieved, leading to the development of high-conductivity solid-state single-ion conducting polymers with leak-free characteristics. Further, using these materials, low-voltage-driven artificial muscles have been prepared that show a large bending strain and millisecond-scale mechanical deformations at 1 V in air without fatigue, exceeding the performance of previously reported polymer actuators. Finally, smart multiresponsive actuators based on tailor-made charged polymers capable of programmable deformation with high force and self-locking without power consumption are suggested as candidates for use in soft robotics.

Multi-stimuli responsive and reversible soft actuator engineered by layered fibrous matrix and hydrogel micropatterns

Soft actuators enable the motion of soft materials such as living organisms, biomaterials, and flexible materials in environments where multiple stimuli are simultaneously present. Although various fast, reversible, and direction-guided actuators exist, their material and structural complexity hinder the construction of a simple fabrication platform for actuators responsive to various environmental conditions with reversible and controlled actuation dynamics. We propose an engineered multi-responsive actuator fabrication platform by combining electrospinning and hydrogel lithography techniques. The fabricated soft actuator is composed of stimuli-responsive hydrogel fibers as an active layer, non-responsive fibers as a passive layer, and a micropatterned hydrogel coupling layer to combine those layers. We demonstrate the reversible bending and unbending of the actuator in response to changes in pH and temperature for less than 2 min. The computational modeling is used to elucidate the bending mechanism of the layered actuator and obtain the key parameters to determine its characteristics. The bending direction is regulated by modulating the mechanical properties of the actuator materials and dimensions of hydrogel micropatterns. The fabrication process is versatile and multi-responsive actuation is achieved by adding another active fiber layer without modifying it. Our study provides an insight into the design of a stimulus-specific, multi-scale, multi-functional soft actuator.

Superhydrophobic, mechanically durable coatings for controllable light and magnetism driven actuators

Although some groundbreaking work has proved the feasibility of non-contact Marangoni propulsion generated by combination of the superhydrophobicity and photothermal effect, there are still challenges including the strong interfacial adhesion, multifunctional structural design and superior durability. In this paper, a simple two-step spraying method is used to prepare superhydrophobic and multi-functional fluorinated acidified carbon nanotubes (F-ACNTs)/Fe3O4 nanoparticles/polydimethylsiloxane (PDMS) coatings. The introduction of Fe3O4 nanoparticles and F-ACNTs not merely improve the surface roughness but also endow the coating with the outstanding magnetic property and photothermal conversion performance. The PDMS can reduce the surface energy and also improve the interfacial adhesion between the nanofillers and the substrate (the filter paper). The superhydrophobicity can be maintained when the material experiences abrasion, near-infrared (NIR) light irradiation and acid treatment, exhibiting outstanding durability. The highly stable superhydrophobic coating introduces a thin layer of air to decrease the drag force between the filter paper and the water surface, and can be used for controlled self-propelled light-driven motion and magnetic-driven motion. The movement can be manipulated by adjusting the direction of the incident NIR light and magnetic field. In particular, the superhydrophobic and superoleophilic coating based actuators can be easily driven to the oil-contaminated area on the water surface by using a magnet for high efficiency oil removal. This work provides a simple and universal strategy for developing intelligent and multi-responsive actuators possessing promising applications in various fields such as environmental protection, micro-robots and biomedicine.

Human skin-inspired multiresponsive actuators based on graphene oxide/polydimethylsiloxane bilayer film: bi-directional transformation of semi-tube into plane sheet/tube under different stimuli

Multiresponsive soft actuators comprised of carbon nanostructured-polymer hybrid smart materials have received enormous attention recently. However, it is always desirable and interesting to explore new types of stimuli which can trigger actuation in such materials. Inspired by human skin which can respond to multiple stimuli, we report here multiresponsive soft actuators based on graphene oxide (GO)-polydimethylsiloxane (PDMS) bilayer structure. These actuators exhibit reversible actuation under different stimuli viz. infrared (IR) light, acetone vapors and temperature. The actuation behavior under the influence of temperature is further investigated with its values in the heating as well as cooling modes. Therefore, the use of the different stimuli imparts the functionalities of photomechanical, vapomechanical, thermomechanical and cryomechanical actuation, respectively to these actuators. The actuators are realized by spin coating of PDMS film (200 μm) on GO film (15 μm) followed by curing at 120 °C. The thermal residual stress generated during curing process causes the structure to become tubular upon release which was then sliced to form semi-tube so that its bi-directional actuation could be observed. The semi-tubular actuators reversibly get transformed into plane sheet shape under the influence of IR light, heating and acetone vapors within about 4, 5 and 1 s, respectively which causes change of curvature from 2.1 to 0 cm−1. Further, it is transformed into full tube shape under the influence of cooling within about 12 s that changes the curvature from 2.1 to 4.2 cm−1. Finally, the actuators are utilized to demonstrate one of the prototype applications as IR light-driven soft gripper. It is believed that these actuators may also find potential applications in the fields of biomimics and realization of artificial intelligence components for military/industrial use.

Electrospun polyamide-6 nanofiber for hierarchically structured and multi-responsive actuator

Actuators that can respond mechanically to external stimulus have attracted great interests because of their great potential in applications of artificial muscle, soft robot, sensor, power generator, and so on. However, the creation of low-cost and multi-responsive actuators from conventional materials is still challenging. Herein, we demonstrate a new kind of hierarchically structured and multi-responsive actuator by twisting electrospun polyamide-6 into coiled yarn (CPY). Due to the presence of microscale and nanoscale cavities, the CPY can reversibly rotate in response to various organic solvents, and the rotation speed is depended on the type of solvent. Capillary force driven shrinkage is suggested as the actuating mechanism of our CPY, which is different from all previously reported coiled yarns. The high coefficient of thermal expansion of polyamide-6 also makes the CPY heat responsive, as the CPY shows contraction upon heating due to the volume expansion induced untwisting. In addition, NIR light and water responsiveness can be further inserted into the CPY by modifying the non-woven with polydopamine prior to twisting as demonstrated here.

Intelligently Actuating Liquid Crystal Elastomer‐Carbon Nanotube Composites

AbstractStrategies for obtaining materials that respond to external stimuli by changing shape are of intense interest for the replacement of traditional actuators. Here, a strategy that enables programmable, multiresponsive actuators that use either visible light or electric current to drive shape change in composites comprising carbon nanotubes (CNTs) in liquid crystal elastomers (LCEs) is presented. In the nanocomposites, the CNTs function not only in the traditional roles of mechanical reinforcement and enhancers of thermal and electrical conductivity but also serve as an alignment layer for the LCEs. By controlling the orientation, location, and quantity of layers of CNTs in LCE/CNT composites, programmed, patterned actuators are built that respond to visible light or electrical current. Photothermal LCE/CNT film actuators undergo fast shape change, within 1.2 s using 280 mW cm−2 light input, and complex, programmed localized deformations. Furthermore, twisting LCE/CNT composite films into a fiber increases uniaxial muscle stroke and work capacity for electrothermal actuation, thereby enabling about 12% actuation strain and 100 kJ m−3 of work capacity in response to an applied DC voltage of 15.1 V cm−1.

Laser Programmable Patterning of RGO/GO Janus Paper for Multiresponsive Actuators

AbstractGraphene oxide (GO) with tunable physical/chemical properties is a versatile material for smart bimorph actuators. Using GO or its derivatives (e.g., reduced GO, RGO) as an active material, actuators can be manipulated under various external stimuli including moisture, light, temperature, and electricity. However, most of these GO‐based actuators respond to a solo stimulus, which limits its cutting‐edge applications in soft robotics. Here, the programmable patterning of RGO/GO Janus paper using a threshold‐controlled direct laser writing (DLW) technology is reported. By combining the RGO/GO Janus paper with a common thermally expansive polymer layer, a moisture, light, and electricity multiresponsive actuator is fabricated, in which the RGO interlayer plays multiroles including moisture‐passive layer, photothermal/electrothermal layer, thermal conductive layer, and inert layer for thermal expansion. As a proof of concept, multiresponsive actuators including a bidirectional cantilever and a smart curtain are fabricated, demonstrating the great potential for developing soft robots.

Gradient Assembly of Polymer Nanospheres and Graphene Oxide Sheets for Dual-Responsive Soft Actuators

Bimorph actuators hold great promise for developing soft robots. However, poor interlayer adhesion between different materials always threatens their stability for long-term usage. In this paper, instead of using a bilayer structure, we reported the gradient assembly of graphene oxide (GO) sheets and polymer nanospheres for developing robust moisture and light dual-responsive actuators. The distribution gradient of poly(methyl methacrylate) (PMMA) nanospheres along the normal direction of a GO paper leads to an asymmetric structure. The front side that mainly consists of GO is quite sensitive to water molecules, which swells upon exposure to moisture, whereas the back side that is rich in PMMA nanospheres expands obviously due to the photothermal effect. The distinct properties of the two sides endow the composite paper with moisture and light dual-responsiveness. Moreover, since GO has been used as a host material, the composite paper shows a moisture-triggered self-healing property, which permits front-to-front and front-to-back healing. The self-healed paper can maintain similar responsive property and reasonable mechanical strength to the pristine one. As a proof of concept, a dual-responsive gripper actuator and a scorpion robot have been fabricated for light and moisture cooperative manipulation. The gradient assembly strategy may open up a new way for developing robust multiresponsive actuators beyond bilayer structures.

Multi-responsive and multi-motion bimorph actuator based on super-aligned carbon nanotube sheets

Multi-responsive actuators have recently aroused intensive research for the requirements of being used in various environments. However, their actuation performances are generally lower than their single responsive counterparts because of the restriction of material selection and complicated structural design. Here, for the first time, a multi-responsive actuator that can respond to four types of stimuli including electricity, near infrared light, humidity, and organic vapors was designed by attaching superaligned carbon nanotubes sheets and coating an ink layer on the both sides of the PET film. The multi-responsive actuator shows fast and reversible actuation with high displacement-to-length ratio of 0.79 under electrical stimulus, and large bending angle of 212ο in 0.55 s at a bending speed of 646ο/s under near infrared light irradiation. The actuator also shows fast response exposing to moisture and volatile organic vapors. The actuator shows a large bending angle within ∼0.1 s when exposed to different organic solvents and recovered its initial shape when the solvent was removed. These performances are in the same level of the record values of the thermal-based bimorph actuators. We demonstrated this actuator as a smart electric-control frequency switch at relatively high on/off frequency up to 17.5 Hz.

A complementary strategy for producing moisture and alkane dual-responsive actuators based on graphene oxide and PDMS bimorph

Smart actuators that enable deforming in a predictable manner under external stimuli have revealed great potential for both traditional and emerging industries. Generally, an asymmetric bilayer structure with one layer active and the other inert to a certain stimulus is essential to realize bending behavior. However, towards the development of dual- or multi-responsive actuators, it still lacks universal and effective strategies for rational design and fabrication of such devices through the simplest way. In this paper, we report a complementary strategy to produce dual-responsive bilayer actuators by combining the moisture-active/alkane-inert graphene oxide (GO) layer with the alkane-active/moisture-inert polydimethylsiloxane (PDMS) layer. The GO@PDMS bimorph actuator can switch its active and inert layers in response to moisture and alkane, respectively, realizing dual-responsive deformation under different actuations. Typical dual-responsive actuators, including a selective air valve and a grip and hook smart claw, are successfully fabricated, demonstrating the capability of effective gases and objects transmission. The complementary bimorph actuator may hold great promise for developing intelligent devices and portable delivery systems.