Thermally drawn fibers as nerve guidance scaffolds

a b s t r a c t Synthetic neural scaffolds hold promise to eventually replace nerve autografts for tissue repair following peripheral nerve injury. Despite substantial evidence for the influence of scaffold geometry and dimensions on the rate of axonal growth, systematic evaluation of these parameters remains a challenge due to limitations in materials processing. We have employed fiber drawing to engineer a wide spectrum of polymer-based neural scaffolds with varied geometries and core sizes. Using isolated whole dorsal root ganglia as an in vitro model system we have identified key features enhancing nerve growth within these fiber scaffolds. Our approach enabled straightforward integration of microscopic topography at the scale of nerve fascicles within the scaffold cores, which led to accelerated Schwann cell migration, as well as neurite growth and alignment. Our findings indicate that fiber drawing provides a scalable and versatile strategy for producing nerve guidance channels capable of controlling direction and accelerating the rate of axonal growth

Design, development, and fabrication of a vibration detecting robotic foot-pad using embedded PVDF strips

Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.Cataloged from PDF version of thesis.Includes bibliographical references (page 31).This thesis shows the design, fabrication, and early characterization process of a slip-sensing foot-pad made from PVDF strips embedded in a rubber molded structure. What follows suggests a proof-of-concept for a design that can be used to detect vibrations on the edges of a teethed structure. The ability to detect localized vibrations in the embedded PVDF sensors in this foot-pad can be used in future studies to measure the contact-patch area and investigate the relationship between the change in such area and incipient slip. The future iterations of the proposed foot-pad can be used to integrate with current foot-pads worn by legged robots such as MIT Cheetah to enable them to predict slippage. An experimental procedure was used to find the effect of a localized stress on the embedded sensors' data. Three iterations of the foot-pad were designed and fabricated. Furthermore, a custom slippage tester was designed and built for future studies. The experimental results suggested that the effect of triggering on the foot-pad was highly localized since it did not affect neighboring sensors. This behavior can be used to measure changes in the contact-patch area since loss of contact between the ground and foot-pad introduces vibrations on the edges of the pad. Though further data collection and mapping should be conducted for this foot-pad to be able to predict slippage, the experimental results suggest that usage of urethane embedded PVDF sensors can be a viable and promising approach in achieving this goal by detecting the localized vibrations induced by the slip incident.by Negin Abdolrahim Poorheravi.S.B

Thermally drawn fibers as nerve guidance scaffolds

Synthetic neural scaffolds hold promise to eventually replace nerve autografts for tissue repair following peripheral nerve injury. Despite substantial evidence for the influence of scaffold geometry and dimensions on the rate of axonal growth, systematic evaluation of these parameters remains a challenge due to limitations in materials processing. We have employed fiber drawing to engineer a wide spectrum of polymer-based neural scaffolds with varied geometries and core sizes. Using isolated whole dorsal root ganglia as an in vitro model system we have identified key features enhancing nerve growth within these fiber scaffolds. Our approach enabled straightforward integration of microscopic topography at the scale of nerve fascicles within the scaffold cores, which led to accelerated Schwann cell migration, as well as neurite growth and alignment. Our findings indicate that fiber drawing provides a scalable and versatile strategy for producing nerve guidance channels capable of controlling direction and accelerating the rate of axonal growth. Keywords: Peripheral nerve repair; Neural scaffold; Fiber drawing; Tissue engineeringNational Science Foundation (U.S.) (Award CBET-1253890)National Institute of Neurological Diseases and Stroke (U.S.) (Grant R01 NS086804-01A1

A Distributed Robot Garden System

Computational thinking is an important part of a modern education, and robotics provides a powerful tool for teaching programming logic in an interactive and engaging way. The robot garden presented in this paper is a distributed multi-robot system capable of running autonomously or under user control from a simple graphical interface. Over 100 origami flowers are actuated with LEDs and printed pouch motors, and are deployed in a modular array around additional swimming and crawling folded robots. The garden integrates state-of-the-art rapid design and fabrication technologies with distributed systems software techniques to create a scalable swarm in which robots can be controlled individually or as a group. The garden can be used to teach basic algorithmic concepts through its distributed algorithm demonstration capabilities and can teach programming concepts through its education-oriented user interface.National Science Foundation (U.S.) (grant 1240383)National Science Foundation (U.S.) (grant 1138967)National Science Foundation (U.S.). Graduate Research Fellowship (1122374