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Recently, actuating materials based on carbon nanotubes or graphene have been widely studied. However, present carbon-based actuating materials are mostly driven by a single stimulus (humidity, light, electricity, etc.), respectively, which means that the application conditions are limited. Here, a new kind of multiresponsive actuating material which can be driven by humidity, light, and electricity is proposed, so it can be used in various conditions. The fabrication is based on the simplest pencil-on-paper method, in which the pencil and paper are both low-cost and easily obtained daily materials. The actuation effect is more remarkable due to a dual-mode actuation mechanism, which leads to an ultralarge actuation (bending curvature up to 2.6 cm−1). Elaborately designed, the actuator can further exhibit a bidirectional bending actuation, which is a significant improvement compared with previous reported thermal actuators. What is more, a colorful biomimetic flower and a smart curtain are also fabricated, fully utilizing the printable characteristic of the paper and multiresponsive characteristic of the actuator. It is assumed that the newly designed actuating material has great potential in the fields of lab-on-paper devices, artificial muscles, robotics, biomimics, and smart household materials. [ABSTRACT FROM AUTHOR]

Most of conventional actuators have only actuation functions, lacking in real‐time sensing signal feedback. In article number 1806057, Luzhuo Chen and co‐workers report a graphene‐based actuator with integrated‐sensing functions. The robot hand based on the actuator can not only manipulate an object, but also sense every actuation state. This work will open new application fields in integrated‐multifunctional devices. [ABSTRACT FROM AUTHOR]

Flexible actuators have important applications in artificial muscles, robotics, optical devices, and so on. However, most of the conventional actuators have only actuation function, lacking in real‐time sensing signal feedbacks. Here, to break the limitation and add functionality in conventional actuators, a graphene‐based actuator with integrated‐sensing function is reported, which avoids the dependence on image post‐processing for actuation detection and realizes real‐time measurement of the shape‐deformation amplitudes of the actuator. The actuator is able to show a large bending actuation (curvature of 1.1 cm−1) based on a dual‐mode actuation mechanism when it is driven by near infrared light. Meanwhile, the relative resistance change of the actuator is −17.5%. The sensing function is attributed to piezoresistivity and thermoresistivity of the reduced graphene oxide and paper composite. This actuator can be used as a strain sensor to monitor human motions. A smart gripper based on the actuators demonstrates perfect integration of the actuating and sensing functions, which can not only grasp and release an object, but also sense every actuation state of the actuator. The developed integrated‐sensing actuator is hopeful to open new application fields in soft robotics, artificial muscles, flexible wearable devices, and other integrated‐multifunctional devices. A graphene‐based actuator with integrated‐sensing function is developed. It realizes real‐time measurements of the shape deformation of the actuator. A smart gripper based on the actuator demonstrates perfect integration of actuating and sensing functions. It can not only grasp and release an object, but also sense every actuation state of the actuator. [ABSTRACT FROM AUTHOR]

A multi‐responsive actuator based on paper and polymer composite is fabricated by a Pencil‐on‐Paper method, which is described by L. Chen, W. Zhang, C. Liu, and co‐workers on page 7244. A colorful biomimetic flower and a smart curtain are also fabricated to demonstrate the applications. This work has great potential in the fields of lab‐on‐paper devices, artificial muscles, robotics, and biomimics. [ABSTRACT FROM AUTHOR]

Abstract Polyimide (PI) is a high-performance polymer with ultrahigh heat stability while carbon nanotube (CNT) possesses high mechanical strength, excellent electrical and thermal conductivity. Here we report a facile and low-cost method free from CNT pre-dispersion for fabricating super-aligned carbon nanotube (SACNT)/PI composite film which combines the advantages of both SACNT and PI. Flexible and scratch-resistant composite film with high CNT content, uniform dispersion of CNTs, and controlled patterned CNT structures can be fabricated easily via in situ imidization. The SACNT/PI composite film exhibits improvement in mechanical strength, Young's modulus, electrical conductivity compared with pristine PI, and shows good thermal stability. Thanks to these superb properties, a flexible, stable, addressable, electromagnetic wave permeable, and high-temperature fast-response multifunctional heater as well as a thermo-mechanical actuator based on SACNT/PI composite film have been demonstrated in this paper. And it also shows great potential in a variety of applications such as flexible/wearable electronics, RFID, other thermo-related devices and so on. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

High-performance actuators have been studied for many years, as they can be used in the fields of artificial muscles, optical switches and biomimetic applications. However, previous actuators mostly had single colors. Actuators with switchable optical properties are still rare. Here, we propose a transparency-switchable actuator based on single-layer superaligned carbon nanotube sheet and paraffin-polydimethylsiloxane composite. When a voltage is applied, the transmittance of the actuator changes from 0.7% to 67% (at the wavelength of 550 nm). At the same time, it bends obviously with a displacement up to 8.4 mm. The actuator is also durable, demonstrating both reversible actuation phenomenon and repeatable switchable transparency for 100 cycles. In addition, since this new type of actuator demonstrates optical property changing together with actuation process, which is smarter compared to previous conventional actuators, a smart window is fabricated, indicating its application in personal privacy protection and intelligent household devices. In a word, this work opens new perspectives on smart windows, optical switches and so on. [ABSTRACT FROM AUTHOR]

A novel round shape electrothermal actuator based on a bimorph structure with a cross-stacked superaligned carbon nanotube film and polydimethylsiloxane has been designed and fabricated. The coated silver film (100 nm thickness) makes the actuator surface like a mirror. Compared with common polymer nanocomposites based electrothermal actuators, our actuator exhibits a distinctive shape change. Due to the different coefficients of thermal expansion of the two material layers, it turns into a convex shape (a concave shape on the other surface) by using low electric field strengths such as < 200 V m −1 . The curvature of the convex shape can be controlled by the voltage precisely. It can lift almost four times of its own weight. The cyclic actuation test shows the excellent stability of the actuator (over 2000 times). Owing to the advantages of low driving voltages, muscle-like responses, distinctive shape changes, mirror-like surface, stability, we think the novel actuator will have great potential usages in various applications, such as artificial muscles, optical devices, microsensors, microrobots, and so on. [ABSTRACT FROM AUTHOR]