More Like this

1. A Venus-flytrap-based actuator

   Volkov, Alexander (February 2021, Nature electronics)

   null (Ed.)

   Conformable electrodes can be used to manipulate the electrical properties of a Venus flytrap, creating actuators that can be wirelessly controlled. 

   more » « less
2. Design of a Highly-Maneuverable Pneumatic Soft Actuator Driven by Intrinsic SMA Coils (PneuSMA Actuator)

   https://doi.org/10.1109/IROS45743.2020.9340803  

   Allen, Emily A.; Swensen, John P. (October 2020, 2020 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS))

   This paper presents the design of a new soft pneumatic actuator whose direction and magnitude of bending may be precisely controlled via activation of different shape memory alloy (SMA) springs within the actuator, in conjunction with pneumatic actuation. This design is inspired by examples seen in nature such as the human tongue, where the combination of hydrostatic pressure and contraction of intrinsic muscle groups enables precise maneuverability and morphing capabilities. Here, SMA springs are embedded in the walls of the actuator, serving as intrinsic muscles that may be selectively activated to constrain the device. The pneumatic SMA (PneuSMA) actuator demonstrates remarkable spatial controllability evidenced by testing under different pressures and SMA activation combinations. A baseline finite element model is also developed to predict the actuator deformation under different pressure and activation conditions. 

   more » « less
3. Strain-controlled Graphene-Polymer Angular Actuator

   https://doi.org/10.1557/adv.2019.276  

   Gilbert, S. Matt; Molnar, Adam; Horton-Bailey, Donez; Yao, Helen Y.; Zettl, Alex (January 2019, MRS Advances)

   ABSTRACT We demonstrate a suspended graphene-(poly(methyl methacrylate) (PMMA) polymer angular displacement actuator enabled by variable elastic modulus of the perforated stacked structure. Azimuthal flexures support a central disc-shaped membrane, and compression of the membrane can be used to control the rotation of the entire structure. Irradiating the PMMA on graphene stack with 5 kV electrons in a convention scanning electron microscope reduces the elastic modulus of the PMMA and allows graphene’s built in strain to dominate and compress the flexures, thus rotating the actuator. 

   more » « less
4. 3D Printed Segmented Flexible Pneumatic Actuator

   Gonzalez, David; Garcia, Jose; Newell, Brittany (September 2019, Conference on Smart Materials, Adaptive Structures, and Intelligent Systems (SMASIS))

   Soft actuators have been studied and analyzed as a new solution for soft robotic technologies. These types of actuators have many advantages due to their predictable deformations and their ease of control, enabling them to hold and move delicate objects performing complex movements in confined spaces. Soft actuators can be made using different manufacturing processes, but the most common is mold casting. However, this manufacturing process involves several steps, increasing the manufacturing time and hindering changes in the design. This paper presents a novel design of a 3D printed soft pneumatic actuator based on additive manufacturing, achieving design versatility and performance. The produced actuator has seven segments that can be individually controlled. The actuators were made using fused deposition modeling (FDM) technology in one continuous process and without support material. The mechanical performance of the soft actuators was demonstrated, analyzing the deformation in the z-axis based on input pressure. 

   more » « less
5. Electrospun liquid crystal elastomer microfiber actuator

   https://doi.org/10.1126/scirobotics.abi9704  

   He, Qiguang; Wang, Zhijian; Wang, Yang; Wang, Zijun; Li, Chenghai; Annapooranan, Raja; Zeng, Jian; Chen, Renkun; Cai, Shengqiang (August 2021, Science Robotics)

   Fibers capable of generating axial contraction are commonly seen in nature and engineering applications. Despite the broad applications of fiber actuators, it is still very challenging to fabricate fiber actuators with combined large actuation strain, fast response speed, and high power density. Here, we report the fabrication of a liquid crystal elastomer (LCE) microfiber actuators using a facile electrospinning technique. Owing to the extremely small size of the LCE microfibers, they can generate large actuation strain (~60 percent) with a fast response speed (<0.2 second) and a high power density (400 watts per kilogram), resulting from the nematic-isotropic phase transition of liquid crystal mesogens. Moreover, no performance degradation is detected in the LCE microfibers after 10⁶cycles of loading and unloading with the maximum strain of 20 percent at high temperature (90 degree Celsius). The small diameter of the LCE microfiber also results in a self-oscillatory behavior in a steady temperature field. In addition, with a polydopamine coating layer, the actuation of the electrospun LCE microfiber can be precisely and remotely controlled by a near-infrared laser through photothermal effect. Using the electrospun LCE microfiber actuator, we have successfully constructed a microtweezer, a microrobot, and a light-powered microfluidic pump. 

   more » « less