Feifei Chen

• PhD
• Associate Professor at Shanghai Jiao Tong University

Soft rubberlike materials, due to their inherent compliance, are finding widespread implementation in a variety of applications ranging from assistive wearable technologies to soft material robots. Structural design of such soft and rubbery materials necessitates the consideration of large nonlinear deformations and hyperelastic material models to...

Soft robots have recently attracted much interest, and dielectric elastomers have shown great promise for soft actuators because of their large voltage-induced deformation. The actuation performance is primarily characterized by the largest deformation, based on the material failure analyses. However, most previous related work usually neglected th...

Electromechanical instability, a significant phenomenon in dielectric elastomers, has been well studied in the literature. However, most previous work was based on the assumption that dielectric elastomers undergo quasi-static deformation. This letter investigates the dynamic electromechanical instability of a dielectric elastomer balloon which ren...

A dielectric elastomer is able to act as an actuator when subjected to an electric field. However, the allowable deformation of dielectric elastomer actuators is severely limited by the material failures. To extend the actuation range, this letter investigates a network of two interconnected dielectric elastomer balloon actuators, each prestretched...

Dielectric elastomer actuators (DEAs) enable to create soft robots with fast response speed and high-energy density, but the fast optimization design of DEAs still remains elusive because of their continuous electromechanical deformation and high-dimensional design space. Existing approaches usually involve repeating and vast finite element calcula...

The Drosophila larva, a soft-body animal, can bend its body and roll efficiently to escape danger. However, contrary to common belief, this rolling motion is not driven by the imbalance of gravity and ground reaction forces. Through functional imaging and ablation experiments, we demonstrate that the sequential actuation of axial muscles within an...

Pinch is an indispensable grasping primitive of human hands and traditional rigid grippers, eminently suitable for handling small-sized and dense objects, but it is rather under-researched in the context of soft robotics. In this article, with the aim of combining the inherent advantages of soft materials and the pinch grasp primitive to enable del...

In this letter, we aim to develop an efficient and accurate kinematic model of a soft wrist that consists of pneumatic bellows configured in parallel, toward dexterous manipulation in confined space. The challenge arises from the distributed nature and deformation-dependency of the generated pneumatic actuation forces along the air chamber, making...

The field of soft robotics is rapidly evolving, and there is a growing interest in developing soft robots with bioinspired features for use in various applications. This research presented the design and development of 3D-printed origami actuators for a soft robot with amphibious locomotion and tongue hunting capabilities. Two different types of pr...

A homogeneous pneumatic soft robot may generate complex output motions using a simple input pressure, resulting from its morphological shape that locally deforms the soft material to different degrees by simultaneously tailoring the structural characteristics and orienting the input pressure. To date, design of the morphological shape (inverse prob...

Soft robots inherit several merits associated with compliant mechanisms, including frictionless, monolithic fabrication, and backlash-free operation. Moreover, the incorporation of soft actuation bestows upon soft robots distinctive advantages in terms of achieving active mobility. However, current soft robot design usually focuses on the motion ra...

Dielectric elastomer actuators (DEAs) possess characteristics closest to human muscles and have been rapidly developed. The rolled DEA is considered more suitable as a driving module due to its ability to output unidirectional deformation. This paper proposes a high-performance actuator, which is connected in series by a spring and a DEA, wherein t...

Prestretch plays an indispensable role in programming the voltage-induced deformation of dielectric elastomer actuators (DEAs). However, lacking rational design methods, the level of prestretch is usually determined through time-consuming experiments and trial-and-error tests. In this paper, we aim to quantitatively determine the optimal biaxial pr...

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 practica...

In this letter, we propose a new class of soft pneumatic linear actuators with single-material, uniaxial deformation, high energy density, and scalability, purely based on periodic curved air channels. The shape of channels is implicitly parameterized by modified triply periodic minimal surfaces (mTPMS) that partition the space into two intertwined...

Twisting motion plays an important role in kinematics of soft robots. However, current twisting actuators usually suffer from complex mechanical design with multiple materials and undesired coupling with bending and stretching motions. In this letter, we propose a new class of soft twisting pneumatic actuators that purely rely on the freeform chamb...

Multimaterials with different modulus can endow soft robots with embodied intelligence that deliver spatially-varying deformation upon actuation. There is an increasing need for design tools that can rigorously and efficiently generate material layouts for desired motions. Here, we present a design paradigm for soft pneumatic multimaterial actuator...

Dielectric elastomers (DEs) are promising soft actuators for use in soft material robots, due to their considerable voltage-induced strain. The actuator's behavior is highly nonlinear due to the complex interplay between the DE, the support structure, and the input electric field, making it a big challenge to automatically design dielectric elastom...

Soft robotics has been receiving increasing attention due to its flexibility and adaptability offered by embodied intelligence. A soft robot may undergo complex motions including stretching, contraction, bending, twisting, and their intricate combinations. Among these basic motions, bending plays a central role when a robot accomplishes tasks such...

Robotics has undergone a profound revolution in the past 50 years, moving from the laboratory and research institute to the factory and home. Kinematics and dynamics theories have been developed as the foundation for robot design and control, based on the conventional definition of robots: a kinematic chain of rigid links.

Functional materials have spurred the advancement of soft robotics with the potential to perform safe interactions and adaptative functions in unstructured environments. The responses of functional materials under external stimuli lend themselves for programmable actuation and sensing, opening up new possibilities of robot design with built-in mech...

Dielectric elastomer actuators (DEAs) are able to undergo large deformation in response to external electric stimuli and have been widely used to drive soft robotic systems, due to their advantageous attributes comparable to biological muscles. However, due to their isotropic material properties, it has been challenging to generate programmable act...

Textile fabrics are compliant, lightweight, and inherently anisotropic, making them promising for the design of soft pneumatic actuators. In this article, we present the design, modeling, and evaluation of a class of soft fabric-based pneumatic actuators (SFPAs) for soft wearable assistive gloves that can simultaneously assist the thumb abduction a...

Dielectric elastomer actuators (DEAs) are a promising actuation technology in soft robotics owing to their large voltage-induced deformation and rapid response. However, most existing DEA design paradigms are empirical or intuitive, lacking the mathematical modeling and optimization methodology to exploit their actuation capabilities for prescribed...

Multimaterial soft robots, composing of integrated soft actuators and a relatively harder body, show great potential to exert higher payloads and support their own weights. This paper proposed a systemic framework to automatically design and fabricate this kind of robots. The multimaterial design problem is mathematically modeled under the framewor...

Soft-bodied robots, due to their intrinsic compliance, have shown great potential for operating within unstructured environment and interacting with unknown objects. This paper deals with automatic design and fabrication of soft robots. From a structure point of view, we synthesize a soft cable-driven gripper by recasting its mechanical design as a...

This paper proposes a novel multiscale concurrent design method to provide insight into the optimal structural design based on micro-architectures, where both the spatially-varying microstructural configurations and their macroscopic distribution are optimized in an integrated manner. A shape metamorphosis technology is developed to interpolate a p...

This paper proposes a structure-material integrated design method in the framework of level sets. A two-scale optimization is performed, where not only is the structural configuration optimized, but the effective properties of the constituent material are also designed by optimizing the configuration of the periodically-arranged microstructures. In...

A dielectric elastomer is able to act as an actuator when it is subject to an electric field. This paper deals with the theoretical analysis of a dielectric elastomer balloon actuator that is driven by a fixed mass of high-pressure air inside and the periodic voltage applied across the balloon wall. The equation of motion involving high nonlinearit...