Research

Title:Development and Testing of a Sub-Carangiform Biomechanical Fish to Mimic Thresher Shark (Alopias sp.) Locomotion

This research explored the morphology and physiology of the thresher shark, Alopias sp., a fish that employs sub-carangiform locomotion. The information gathered during this research facilitated the development of a biomimetic robotic fish tail. A slender beam encased in a silicone polymer mold, geometrically similar to the thresher shark’s anatomy, was mechanically oscillated to produce sub-carangiform locomotion. The oscillations were induced using an attached servomotor, which was controlled by a BASIC Stamp microcontroller. Tests conducted in an aquarium tank indicated that a transparent plastic beam had the required modulus of elasticity for insertion into a biomimetic tail. A 3D model of the tail was designed using Solid Works. The mold for the silicone tail was also designed using Solid Works, and was created using a computer numerical control (CNC) machine with ShopBot software. After curing, the tail’s motion was studied using image analysis. The tail design was based on morphometric data of thresher sharks.

Research

Title: Analysis of PVC Foam and Carbon Nanofiber Syntactic Foam

Composite materials are now widely used in daily life and they undergo high loading rate deformations in many of their current applications. Although mechanical characteristics of materials are known to be dependent on their loading rate, the high strain rate properties and dynamic failure mechanisms of composites are not well understood. This research used in-house developed advanced instrumentation, called Hopkinson bar, to develop such knowledge about emerging composite materials. Both traditional static and high strain rate compression tests were conducted on samples of Polyvinyl Chloride (PVC) foam as well as on samples of syntactic foam that contain glass microballoons of varying densities in different volumes as well as 1% carbon nanofibers (CNF).

In static compression tests, the PVC foam samples displayed an increase in every compressive property (yield strength, plateau strength, and elastic modulus) as their density increased, while the trends displayed by CNF syntactic foam samples were complex and depended on the volume fraction and density of microballoons used in the specimen. In the high strain rate testing using Hopkinson bar, the lowest density PVC foam displayed the highest specific modulus, while the syntactic foam containing high density microballoons in high volume fraction displayed the highest specific yield strength. The study demonstrates strain rate dependence of mechanical properties of porous materials and illustrates the need to account for the strain rate in the design criteria for a structure utilizing foams.

Research

Title: TCI Apparatus for Creep Behavior of Recycled HDPE Using Stepped Isothermal Method

This research is concerned with the compressive creep behavior of High Density Polyethylene (HDPE), a viscoelastic material commonly used to manufacture polymeric piling, decking, and fender elements. In this research, we developed a temperature control instrument (TCI), an experimental apparatus to control the temperature of a specimen as it is mechanically compressed. This apparatus facilitates examination of the effect of combined temperature cycles and different loading rates on the durability of recycled HDPE specimen bars. Through a series of cyclic temperature variations, we collected experimental data and analyzed it to obtain conclusions about the material’s strength under different loading rates and at different temperatures. The Stepped Isothermal Method (SIM) has been adapted to study the time and temperature dependent compressive creep of HDPE.

Research

Title: MATLAB Modeling of Retina Structure and Function

Research at the intersection of neuroscience and engineering offers the promise of neuro-mechanical prostheses. The success of cochlear implants and interest in brain function, robotics, and quality of life issues has motivated a search for an ocular prosthesis. Recently retinal implants have successfully offered low-resolution sight to the blind, but an incomplete understanding of the structure and function of the retina is preventing a prosthesis from “plugging” into the optic nerve. In this research, we used our current knowledge of retina anatomy to develop a MATLAB/SIMULINK model that mimics the structure and function of the retina. Preliminary simulation efforts reveal that our anatomically correct MATLAB/SIMULINK model is effective in detecting contrast. Validating the MATLAB simulation model with clinical data can support the accuracy of our current understanding of the structure and function of the retina. Moreover, our MATLAB simulation approach can allow us to test alternative hypotheses of structure and function of the retina, which will motivate new clinical investigations. Finally, new clinical knowledge will lead to better simulation models. Interplay and synergy between the modeling and clinical approaches can potentially accelerate and enhance our understanding of how the eye processes images of our physical world.

Research

Title: iPhone-Controlled Robotics Project

This effort focused on building and exploring a mechatronic project that can be remotely controlled using the iPod or iPhone mobile devices. Whereas on-going iPhone-controlled projects in the lab (e.g., iPhone-controlled Create robot, Smart-House, and RC-Truck) involve physically mounting a router and a MAKE microcontroller on the project, our platform separates the router and the MAKE microcontroller from the mobile platform, thus reducing its overall weight. Specifically, our effort resulted in the development of a platform wherein: (1) a remote user interacts with a graphical user interface on a mobile device to send control commands over a Wi-Fi netwrok; (2) a MAKE microcontroller interfaced to a wireless router receives the remote user’s control commands over the Wi-Fi network; (3) the MAKE microcontroller serially communicates the control commands to a Basic Stamp microcontroller; (4) the Basic Stamp microcontroller transmits the control commands to a mobile robot using an RF-transceiver, receives sensory data from the robot using the RF-transceiver, and serially communicates the received sensory data to a Matlab program running on a PC; and (5) a MATLAB program stores, display, and plots the received sensory data, which can be analyzed in real-time and used to make new control decisions. In on-going effort, we will eliminate the Basic Stamp microcontroller and serially interface the RF-transceiver and MATLAB directly to the MAKE microcontroller. Moreover, we plan on replacing the role of MATLAB with an iPhone application so that the sensory data can be stored and displayed on the iPhone itself. This research involved all principles of robotic systems, including mechanical and electrical subsystem design, hardware interfacing, and programming.

Research

Title: Stochastic Surface Effects on Nanobeam Behavior

The turn of the century brought forth an invigorated pursuit to conquer the nanotechnological world. With the advent of highly powerful tools in microscopy and subatomic probes, the utilization of novel particles and nanosructures has led to a wide variety of research and applications ranging from medicine, robotics, supercomputing, physics and the like. This effort focused on examining the stochastic behavior on the effective properties of nanowires. Under Prof. Dingreville’s guidance, we reviewed the prior literature to understand the scientific background and underlying theories. Next, using a perturbation method, we initiated the development of a new formulation for the study of nanowire manufacturing. While our initial effort has focused on the surface effects in nanobeam behavior, we conducted another parallel study to account for the buckling effect of the material itself.

Research

Title: Art as an Integrator for Research, Education, and Outreach

AKnowledge can be obtained in multiple ways. Traditionally art classes are thought to be hands-on with an open environment that promotes creativity. In contrast, math and science classrooms are thought to be restrictive with little to no room for creativity. It has been proven that when students are more involved in classrooms they connect better with their field of study. In this effort, we are exploring the use of art as a vehicle to transmit STEM knowledge to students. Specifically, this informal approach is being investigated to introduce to students fundamental concepts in materials science, mechanical engineering, and mathematics. Our main goals are: • Establish an interdisciplinary collaborative team consisting of NYU-Poly researchers, NYC school teachers and students, and local artists • Spread scientific and artistic literacy • Infuse and stimulate knowledge, skills, creativity, versatility and a sense of wonder among youngsters • Integrate scientific activities into artistic creations and vice-versa • Broaden the ties of NYC-Poly with local community In on-going effort, we plan to develop “art objects,” and hold exhibits that illustrate the use of various materials used in art.