Abstract-Hyper-redundant manipulators can be fragile, expensive, and limited in their flexibility due to the distributed and bulky actuators that are typically used to achieve the precision and degrees of freedom (DOFs) required. Here, a manipulator is proposed that is robust, high-force, low-cost, and highly articulated without employing traditional actuators mounted at the manipulator joints. Rather, local tunable stiffness is coupled with off-board spooler motors and tension cables to achieve complex manipulator configurations. Tunable stiffness is achieved by reversible jamming of granular media, which-by applying a vacuum to enclosed grainscauses the grains to transition between solid-like states and liquid-like ones. Experimental studies were conducted to identify grains with high strength-to-weight performance. A prototype of the manipulator is presented with performance analysis, with emphasis on speed, strength, and articulation. This novel design for a manipulator-and use of jamming for robotic applications in general-could greatly benefit applications such as human-safe robotics and systems in which robots need to exhibit high flexibility to conform to their environments. [6], and to create a variable stiffness endoscopic tube [7]. The combination of these projects highlights the primary benefits of utilizing jamming for robotics:it allows robots to be more human-safe, inexpensive, and robust compared to most technologies that have traditionally been used for such applications.The goal of this paper is to further the use and understanding of jamming for engineering applications. Specifically, we present the design and analysis of a robotic manipulator composed of 1) serial modules that can transition between rigid and flexible states via jamming and 2) tension cables running along the length of the manipulator and whose lengths are controlled by spooler motors. We previously demonstrated this robotic architecture of coupling locally tunable stiffness with global actuation as a thrust toward soft robotics [8] [9]. One of the main benefits of this type of system is that by eliminating the need for distributed-and often rigid and bulky-actuators throughout the robot, the system can be more robust and flexible, enabling it to conform to its environment better. In addition, the cost of the robot can be drastically reduced.In this paper we also begin to explore how grain properties affect the performance of jammed systems. Specifically, we seek to maximize the strength-to-weight ratio of jammed systems. This is an important figure of merit for manipulators, where the robot must be able to support its own weight in addition to any payloads.Because granular systems inherently lack mechanical structure in their unjammed states, their flexibility and high DOFs can be beneficial for hyper-redundant robotic systems such as a manipulator. Most approaches in hyper-redundant robotics have involved employing distributed and rigid pneumatic or electromagnetic actuators. Much of the effort in this area has been in dev...

Although thermoplastic materials are mostly derived from petro-chemicals, it would be highly desirable, from a sustainability perspective, to produce them instead from renewable biopolymers. Unfortunately, biopolymers exhibiting thermoplastic behaviour and which preserve their mechanical properties post processing are essentially non-existent. The robust sucker ring teeth (SRT) from squid and cuttlefish are one notable exception of thermoplastic biopolymers. Here we describe thermoplastic processing of squid SRT via hot extrusion of fibres, demonstrating the potential suitability of these materials for large-scale thermal forming. Using high-resolution in situ X-ray diffraction and vibrational spectroscopy, we elucidate the molecular and nanoscale features responsible for this behaviour and show that SRT consist of semi-crystalline polymers, whereby heat-resistant, nanocrystalline β-sheets embedded within an amorphous matrix are organized into a hexagonally packed nanofibrillar lattice. This study provides key insights for the molecular design of biomimetic protein- and peptide-based thermoplastic structural biopolymers with potential biomedical and 3D printing applications.

An on-site mobile robotic platform autonomously constructed an open dome with complex curvature and variable wall thickness.

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Three-dimensional (3D) printing technologies are increasingly used to convert medical imaging studies into tangible (physical) models of individual patient anatomy, allowing physicians, scientists, and patients an unprecedented level of interaction with medical data. To date, virtually all 3D-printable medical data sets are created using traditional image thresholding, subsequent isosurface extraction, and the generation of .stl surface mesh file formats. These existing methods, however, are highly prone to segmentation artifacts that either overor underexaggerate the features of interest, thus resulting in anatomically inaccurate 3D prints. In addition, they often omit finer detailed structures and require time-and labor-intensive processes to visually verify their accuracy. To circumvent these problems, we present a bitmap-based multimaterial 3D printing workflow for the rapid and highly accurate generation of physical models directly from volumetric data stacks. This workflow employs a thresholding-free approach that bypasses both isosurface creation and traditional mesh slicing algorithms, hence significantly improving speed and accuracy of model creation. In addition, using preprocessed binary bitmap slices as input to multimaterial 3D printers allows for the physical rendering of functional gradients native to volumetric data sets, such as stiffness and opacity, opening the door for the production of biomechanically accurate models.