This review covers recent advancements in the field of bioinspired soft robotics, with a primary focus on the last 4 years (2017)(2018)(2019)(2020). The review serves as a toolbox for an interdisciplinary audience interested in the most recent bioinspired soft robotic technologies. In particular, it highlights and explores the vital components of soft robots, focusing on the enabling mechanisms and their biological inspirations. The first section discusses the materials used to fabricate soft bio inspired robots. Soft bioinspired actuation and sensing are then discussed, exploring their capabilities and implementation by researchers. Existing challenges and future potentials of bioinspired soft robots are addressed in the concluding remarks. This review provides engineers and scientists with the latest technological advancements and information needed for designing and developing the next generation of soft bioinspired robotic systems. The future applications of these robots will be grand and limitless. Materials Used for Bioinspired Sensors and ActuatorsClassical robotic systems are comprised of rigid bodies, actuators, and sensors. Unfortunately, many of these well-developed actuators and sensors are not transferable to soft bodies. Thus, researchers working in soft robotics need to reinvent actuators and sensors for soft moving bodies. Biological organisms can be an excellent inspiration for designing these soft actuators and sensors, allowing for their integration in both soft and rigid bodies. The design process of soft actuators and sensors have to be initiated with material selection and composition, for they are foundations upon which the actuators and sensors will be built around. Presently, a diversified list of materials has been used in the development of soft robotic systems. This section will cover some of the latest advancements in the last 4 years in the area of material selection and composition for the design and development of soft bioinspired actuators and sensors.During the past 4 years, researchers have produced soft bioinspired actuators and sensors using biological material such as muscle tissue, [23,24] and plant fibers; [25] carbon-based materials such as graphite and graphene oxide (GO) [26][27][28][29][30][31] and carbon nanotubes (CN); [32,33] hydrogel materials such as poly(Nisopropylacrylamide) (PNIPAM), [34,35] liquid crystal elastomers (LCE), [36] dielectric elastomers (DE), [37] and ionic polymermetal composites (IPMC). [38] An overview of these materials (Figure 1), along with their underlying mechanisms, are discussed below.Biological systems can perform complex tasks with high compliance levels. This makes them a great source of inspiration for soft robotics. Indeed, the union of these fields has brought about bioinspired soft robotics, with hundreds of publications on novel research each year. This review aims to survey fundamental advances in bioinspired soft actuators and sensors with a focus on the progress between 2017 and 2020, providing a primer for the materials used i...

Octopuses utilize their suckers for a myriad of functions such as chemo‐ and mechanosensing, exploring and manipulating objects, anchoring the body during crawling, and navigating through narrow passages. The sucker attachment mechanism grants the octopus the ability to perform many of these tasks. The goal of this study is to analyze sucker function and control through the assessment of pull‐off forces under different conditions. Sucker pull‐off forces are measured in Octopus bimaculoides (three females, seven males), when the arm is intact, amputated, and amputated with the suckers punctured. Greater sucker pull‐off forces are observed for amputated arms, plausibly indicating that the brain and/or the interbrachial commissure are responsible for triggering early sucker detachment in the intact animal. In addition, after piercing and compromising the sucker cavity, pull‐off force significantly decreases, indicating that the primary mechanism for sucker attachment is suction, and is less dependent on adhesion. These results provide new insights into the control and function of octopus suckers that can be integrated into the design and development of soft robot arms for aquatic applications.

No abstract

Skins with asymmetric kirigami scales and soft spikes are integrated to the surface of a base self‐burrowing robot, which consists of a soft one‐segment extending actuator. Friction anisotropy is observed at the interfaces between the burrowing robots and different granular materials. Its effects on the pulling resistance and burrowing characteristics are studied. The results demonstrate that the development of friction and friction anisotropy is affected by the characteristics of the granular material, the asymmetric skins, and the relative size of the asymmetric features to the granular particles. Robots with scales or spikes aligned along the upward direction burrow faster than those aligned against the upward direction, especially in relatively coarser granular materials. Particle image velocimetry analysis on the particle displacement fields around the actuator reveals the complexity of dry granular material interactions with soft robots, implying that aligned scales or spikes can impact the distribution of friction preferentially, opening up many possibilities for thoughtful material and geometry‐based manipulation of friction in the design and optimization of future soft burrowing robots for more versatile locomotion capabilities.

No abstract