The inherent compliance of soft materials imbues robots,generally referred to as soft robots,with particular advantages in producing adaptive and safe interactions.However,the mainstream design paradigms of soft robot...The inherent compliance of soft materials imbues robots,generally referred to as soft robots,with particular advantages in producing adaptive and safe interactions.However,the mainstream design paradigms of soft robots have been focused on pursuing large free motions only,usually at the expense of greatly decreased stiffness,leading to limited capability of withstanding external loads in interactive scenarios.There is a pressing need to incorporate the interaction specifications at the design stage to embody soft robots with not only proper deformability but equally importantly,considerable stiffness to perform complex tasks in practical applications.Here,inspired by the dexterity of human hands,we propose a computational design framework for soft grippers with a focus on improving their interaction performance in power grasping or precision grasping mode.The design paradigm rests on attaching a relatively stiffer skeleton layer to the parametric pneumatic networks based actuator which is widely used due to the geometric advantage,and the skeleton layout is designed for customized interaction conditions by a level set based topology optimization approach.As expected,the optimized skeleton layouts exhibit specified structural features highly relevant to the predefined concentrated loads for precision grip or distributed loads for power grip,which physically implies the compromise between deformability and stiffness.Since the interaction forces are difficult to measure in situ,we devise power and precision grasping scenarios and evaluate the critical actuation pressure of the object’s falling instead.The experiments qualitatively demonstrate the superiority of each specified design.This work represents an initial step toward the rational design for interaction in soft robots.展开更多
The intrinsic compliance of soft materials endows soft robots with great advantages to achieve large deformation and adaptive interactions in grasping tasks.However,current soft grippers usually focus on the in-plane ...The intrinsic compliance of soft materials endows soft robots with great advantages to achieve large deformation and adaptive interactions in grasping tasks.However,current soft grippers usually focus on the in-plane large deformation and load capacity but ignore the effect of out-of-plane external loads,which may lead to instability in practical scenarios.This problem calls for stiffness design along multiple directions to withstand not only in-plane interacting forces with objects,but also unexpected outof-plane loads.In this paper,we design a new type of soft finger by embedding an endoskeleton inside the widely-used PneuNets actuator,and the endoskeleton layout is optimized to achieve a remarkable bending deflection and limited lateral deflection under combined external in-plane and out-of-plane loads.Based on the multi-objective topology optimization approach,the key structural features of the optimized endoskeleton are extracted and parameterized.The multi-material soft fingers are fabricated by the silicone compound mold method.Static and dynamic experiment results validate that the soft gripper with endoskeleton embedded exhibits remarkably improved out-of-plane stiffness,without sacrificing the in-plane bending flexibility,and leads to more stable grasping.展开更多
基金the National Natural Science Foundation of China(Grant Nos.51905340 and 91948302)the Shanghai Sailing Program(Grant No.19YF1422900)。
文摘The inherent compliance of soft materials imbues robots,generally referred to as soft robots,with particular advantages in producing adaptive and safe interactions.However,the mainstream design paradigms of soft robots have been focused on pursuing large free motions only,usually at the expense of greatly decreased stiffness,leading to limited capability of withstanding external loads in interactive scenarios.There is a pressing need to incorporate the interaction specifications at the design stage to embody soft robots with not only proper deformability but equally importantly,considerable stiffness to perform complex tasks in practical applications.Here,inspired by the dexterity of human hands,we propose a computational design framework for soft grippers with a focus on improving their interaction performance in power grasping or precision grasping mode.The design paradigm rests on attaching a relatively stiffer skeleton layer to the parametric pneumatic networks based actuator which is widely used due to the geometric advantage,and the skeleton layout is designed for customized interaction conditions by a level set based topology optimization approach.As expected,the optimized skeleton layouts exhibit specified structural features highly relevant to the predefined concentrated loads for precision grip or distributed loads for power grip,which physically implies the compromise between deformability and stiffness.Since the interaction forces are difficult to measure in situ,we devise power and precision grasping scenarios and evaluate the critical actuation pressure of the object’s falling instead.The experiments qualitatively demonstrate the superiority of each specified design.This work represents an initial step toward the rational design for interaction in soft robots.
基金supported by the National Natural Science Foundation of China (Grant Nos.52275026 and 91948302)the State Key Laboratory of Structural Analysis for Industrial Equipment (Grant No.GZ21117)。
文摘The intrinsic compliance of soft materials endows soft robots with great advantages to achieve large deformation and adaptive interactions in grasping tasks.However,current soft grippers usually focus on the in-plane large deformation and load capacity but ignore the effect of out-of-plane external loads,which may lead to instability in practical scenarios.This problem calls for stiffness design along multiple directions to withstand not only in-plane interacting forces with objects,but also unexpected outof-plane loads.In this paper,we design a new type of soft finger by embedding an endoskeleton inside the widely-used PneuNets actuator,and the endoskeleton layout is optimized to achieve a remarkable bending deflection and limited lateral deflection under combined external in-plane and out-of-plane loads.Based on the multi-objective topology optimization approach,the key structural features of the optimized endoskeleton are extracted and parameterized.The multi-material soft fingers are fabricated by the silicone compound mold method.Static and dynamic experiment results validate that the soft gripper with endoskeleton embedded exhibits remarkably improved out-of-plane stiffness,without sacrificing the in-plane bending flexibility,and leads to more stable grasping.
