Abstract-- We present a computational framework for simulating filaments interacting with rigid bodies through contact. Filaments are challenging to simulate due to their codimen-sionality, i.e., they are one-dimensional structures embedded in three-dimensional space. Existing methods often assume that filaments remain permanently attached to rigid bodies. Our framework unifies discrete elastic rod (DER) modeling, a pressure field patch contact model, and a convex contact formulation to accurately simulate frictional interactions between slender filaments and rigid bodies - capabilities not previously achievable. Owing to the convex formulation of contact, each time step can be solved to global optimality, guaranteeing complementarity between contact velocity and impulse. Finally, we demonstrate its applicability in both soft robotics, such as a stochastic filament-based gripper, and deformable object manipulation, such as shoelace tying, providing a versatile simulator for systems involving complex filament-filament and filament-rigid body interactions.

Robotics is the science of designing and constructing machines capable of movement, perception, and cognition to assist humans in performing various tasks. Inspired by living organisms, using soft matter in robot design has gained significant attention in recent decades. The inherent compliance of soft bodies allows them to adapt to complex environments, enabling innovative applications in fields such as healthcare, agriculture, and the food industry [1-10]. Given the potential of soft robots, various functional materials, such as liquid crystal elastomers, pneumatic actuators, and light-driven systems, have been explored as actuators due to their ability to deform in response to diverse external stimuli. However, the intrinsic compliance and nonlinearity of soft materials pose significant challenges in achieving precise and effective deformation control, which limits their practical effectiveness in real-world applications. A widely adopted approach to addressing this challenge is using bilayer structures in soft robot design. Inspired by natural phenomena such as the opening of pea pods, a bilayer structure consists of two layers--an top and a bottom layer--adhered at their interface [11], as illustrated in Figure 1A. When one layer undergoes expansion, a mismatch strain arises at the interface.

Spring-driven jumping robots use an energised spring for propulsion, while the onboard motor only serves as a spring-charging source. A common mechanism in designing these robots is the rhomboidal linkage, which has been combined with linear springs (spring-linkage) to create a nonlinear spring, thereby increasing elastic energy storage and jump height for a given motor force. The effectiveness of this spring-linkage has been examined for individual designs, but a generalised design theory of this class of system remains absent. This paper presents an energetics analysis of the spring-linkage and provides insight into designing an ideal constant force spring, which stores the maximum energy for a given motor force. A quasi-static analysis shows that the force-displacement relationship of the spring-linkage changes with the orientation and type of the spring, but is independent of the linkage scale. Combining different types and orientations of springs within the linkage enables higher elastic energy storage than using single springs. Placing two translational springs at the diagonals of the rhomboidal linkage creates an ideal spring that could increase the jump height of prior robots by 50-160%.

Abstract-- We present a novel general model that unifies the kinematics of constant curvature and constant twist continuum manipulators. Combining this kinematics with energy-based physics, we derive a linear mapping from actuator configuration to manipulator deformation that is analogous to traditional robot forward kinematics. The combination of generality and linearity makes the model useful for control and planning algorithms. Finally, our model is shown to be accurate through experimental validation on manipulators with pneumatic artificial muscles. I. INTRODUCTION While the motion of traditional robots comes from their discrete joints, a continuum manipulator moves by deforming along its entire arc. These manipulators are often composed of rigid skeletons and soft actuators.

Bio-medical engineers have created a robot so fast moving that it can catch an insect with its'tongue' - after studying nature's springiest amphibians for inspiration. Chameleons, salamanders and toads were the inspiration for a new range of soft robots which can carry out automated tasks requiring a range of movements at a fast pace. Industrial and biomedical engineers studied the stored elastic energy that the animals use to launch their sticky tongues in order to replicate the fast, non-robotic movement. Catching unsuspecting insects located up to one-and-a-half body lengths away the amphibians high-speed movements inspired researchers at the Purdue University's College, Indiana, U.S Similar to the chameleon's tongue strike, a pre-stressed pneumatic soft robot is capable of expanding five times its own length, catch a live fly beetle and retrieve it in just 120 milliseconds Catching unsuspecting insects located up to one-and-a-half body lengths away the amphibians high-speed movements helped researchers at the Purdue University's College of Engineering, Indiana, U.S. to develop a new class of entirely soft robots. These bio-inspired robots are fabricated using stretchable polymers similar to rubber bands, with internal pneumatic channels that expand upon pressurisation.

The latest robotic cockroach can jump more than five feet in the air, and flip itself over to continue scurrying. Using a new method for storing energy and a height-adjustable trigger, the robo-roach can achieve more ground than those which rely solely on crawling. Though the enhanced jumping capabilities have been built into a small package for the project, the concept has potential to be scaled up for much larger robotics systems. The bug crawls across a desk before opening its'wings' to jump high in the air. The JumpRoACH features a height-adjustable trigger, allowing it to jump between 1.1 and 1.62 meters (3.6 – 5.2 feet) JumpRoACH has six feet for crawling and can move at a speed of up to .62 meters (2 feet) per second.