SUNFEST at Penn
The Implementation of the Segway Robotic Mobility Platform (Rmp) For Autonomous Navigation
Advisor: Professor Vijay Kumar and James Keller
ABSTRACT: A difficult problem in robotics is enabling a robot to navigate autonomously through a previously unexplored indoor environment. Part of this difficulty stems from the stringent requirements on the mobility and the power of a robotic platform. It is necessary that the platform has sufficient maneuverability to operate in a cluttered area and that it has sufficient power to carry the necessary sensors to operate autonomously. The Segway Robotic Mobility Platform (RMP) combines unusually high mobility with the power to carry a sufficient number of sensors to navigate in an indoor environment. This paper discusses how, using a laser range finder, a stereo camera, and the Segway's on-board encoders, the Segway RMP can be enabled to perform tasks of autonomous navigation while navigating through an area with obstacles. View Paper | View Slides
Experimental Development of the Mobile Vestibular Platform
Advisor: Dr. Daniel D. Lee
ABSTRACT: Cable robotics is an emerging research field in robotics which has the potential to be applied to a variety of practical purposes and tasks. Applications dealing with short distance transportation of hazardous materials as well as the handling of and interaction around these materials are several of the major tasks that can be handled efficiently and safely by cable robots, reducing the risk to employee lives as well as the need for more complex methods to accomplish the same task. Environmental monitoring of deep mines, hostile environments, and other locations inaccessible or uninhabitable by humans is another very realistic and viable application of cable robotics, allowing for the current sensory information about a remote location to be known at any time. Because of the simplistic nature of the design of cable robots, entire networks can also be implemented in order to cooperate with one another with the purpose of completing a particular task and reacting to sudden changes in sensory data extracted from the surrounding environment.
The particular robot being developed in this project is a versatile, cable driven robotic platform capable of movement in a three-dimensional space, and is named the mobile vestibular platform (MVP). It is designed to be versatile in that the system can easily accommodate several different sensory functions, while also being low budget and light weight. The particular implementation used allows for high precision motor control and thus higher precision in the movement of the robotic platform through space, while a Matlab program handles calculation tasks and remote operation of the platform from a central processing PC. View Paper | View Slides
Visualization of Reachability Graphs in Hybrid Systems
Microsoft SUNFEST Fellow
Advisor: Professor Vijay Kumar
ABSTRACT: Hybrid Systems is a control technique that is used in robotics. It combines sets of continuous differential equations with a discrete system that adjusts them based on multiple criteria, and uses this to simulate or control a system. The BIOCharon team takes this technique and uses it to simulate biological systems. These systems can contain many variables, and the end result of the simulation is a state space that is not easily understandable or viewable. GGV (short for Gridded Graph Viewer) is a program that allows a user to do specific "reachability analysis" on the system as well as presents a good visualization for it. View Paper | View Slides
Conquering Tissue-Sensor Contact -- For A Breast Cancer Detector
Advisor: Dr. Britton Chance
ABSTRACT: Current imaging diagnostic techniques demand better detection methodology to non-invasively monitor the angiogenesis of breast cancer. One of the emerging imaging techniques is to use near infrared (NIR) light to image the biophysical signs of cancerous tumor cells using optical spectroscopy. Two of the problems that arise from implementing such a method are optode-tissue coupling while fitting the contours of the breast and pressure equalization. The purpose of this project is to build upon the previous work in fabricating a device to counteract the two problems. Over the 10-week span of the SUNFEST program, an improved breast cancer detection probe has been designed, built, and validated.
This new prototype introduces two new components: Poron Quick Recovery Polyurethane Foam and a rigid delrin backing plate. The foam allows localized articulation at specific sites to fit the contours of the breast while the rigid plate aids in equalizing the pressures. Another vital advance of this device is implementation of an improved photodiode with 9.7mm * 9.7mm active area, which permits a high signal-to-noise ratio. Experiments have been conducted to validate this prototype and they have shown promising results. The next stage will involve clinical trials in monitoring angiogenesis in-vivo. View Paper | View Slides
Intervertebral Disc Imaging and Analysis Protocol Enhancement
Advisors: Dawn M. Elliott, PhD and Chandra S. Yerramalli, PhD
ABSTRACT: Scientists in human tissue research often use animal tissue as alternative for human samples. Animal tissue samples are desired for their low cost and greater availability compared to human tissue. In human spine research, mouse, rat, and sheep intervertebral discs are often used as mechanical models for the human disc. They have proven effective models because they often posses mechanical properties similar to human discs. However, no one has explored whether those animal models are good geometric models of human discs. If they are, it may establish an even stronger argument for the use of these animal tissues as alternatives to human tissue. An intervertebral disc imaging and analysis protocol was devised at this lab, enabling the assessment of the geometric properties of this disc. However, additional measurements were needed so that more geometric properties could be examined. I set out to improve and expand the original protocol so that it may be used for this purpose. View Paper | View Slides
Development of a Novel Therapy For Ocular Neovascularization
Advisors: Elaine Wu and Dr. Tolentino
ABSTRACT: Age-related macular degeneration (AMD), the leading cause of blindness in the developed Western World, affects over 10 million Americans. Intravitreal injection of triamcinolone acetonide (TA) has been successfully used in the clinic to treat age-related macular degeneration and other similar neovascular diseases, but its mechanism of action is still unclear. However, this experiment sheds light on the subject and leads to a better understanding of the investigational therapy for human disease. It is hypothesized that TA inhibits development of neovascularization (NV) by reducing Vascular Endothelial Growth Factor (VEGF). The goal of this project is to determine if TA decreases VEGF, a protein associated with the development of NV in AMD and other retinopathies. View Paper | View Slides
Integrated Electrochemical Gating of Carbon Nanotube Fets for Biosensing Applications
Advisor: Dr. A.T. Charlie Johnson, Physics and Astronomy
ABSTRACT: Carbon nanotubes have emerged as the leading candidate of electronic materials used for future nanoscale chemical and molecular sensors. Recently, nanotube field effect transistors (CNFETs) have been exploited as biodetectors of the thyroid hormone, triiodothyronine (T3). Although significant progress has been towards the development of actual nanotube based sensor devices, the next challenge is to integrate the devices into a single chip. Numerous gate configurations to CNFETs have been proposed, but few have been shown to be effective, and even fewer can be integrated to a chip. An electrolytic "tip" gate design has been shown to be more effective than the conventional backgate geometry. The drawback to the "tip" gate geometry lies in the fact that an external electrode is required to gate the devices. In this paper, a novel integrated gate design is proposed. Lithographically patterned electrodes on the chip surface are fabricated to effectively gate CNFET devices. View Paper | View Slides
The Hand-Held Breast Cancer Detector: A 2-D Phased Array System
Advisor: Dr. Britton Chance
ABSTRACT: Presently, there are well known non-invasive methods in the detection of breast cancers. The most important include Magnetic resonance, X-ray, and Ultra-sound mammograms. However, due to their high cost, inconvenience, and time considerations, alternative methods are emerging. The Hand-Held Breast Cancer Detector (HHBCD) is designed to be an inexpensive and convenient way to replace other mammograms for some circumstances. It can detect small size tumors (1mm) up to 1 cm into the skin. The goal of this project is to expand the detection range to 3 cm. The device is based on the interference of two paired anti-phase near-infrared light (NIR) sources, a Photomultiplier tube detector (PMT) that detects a portion of this light, and a 2-D phased array method that discerns inequalities in the breast tissue. Most of the efforts put into the device were dedicated to improved signal interpretation, a more effective light source driver, and a shut-off protection system. The discussed individual parts were built but time did not permit them to be integrated. Successful completion of the device could prove useful for quick tumor detection and as a localization tool. View Paper | View Slides
Minimization of Distortion And Increasing Resolution In Wide-Angle Viewing by Means of Actuated Micro-Mirrors
Advisor: Dr. Suresh G. K. Ananthasuresh and Dr. Andrew Hicks
ABSTRACT: Mirrors of numerous shapes, including spherical and paraboloidal mirrors, have been employed for many different commercial and industrial uses, despite their tendency to distort and warp images. When the object in consideration is planar and oriented normal to the optical axis of the mirror, the amount of distortion introduced by a paraboloidal mirror is less than the distortion introduced by a spherical mirror. Previous research has found an optimal mirror shape that minimizes distortion of images of planar objects normal to their optical axes.
The goal of this project was to design and construct a single-axis micro-mirror, to form the basis for future work. The micro-mirror construction used a (110) silicon wafer. The design consists of a square mirror supported by two torsional beams. Several design variations were considered to see how these variations affected the fabrication. Due to time limitations, the construction was not completed. It was achieved through the photoresist stripping of the bottom pattern step. Although, the construction was not completed, microfabrication techniques were learned such as mask drawings design, resist processing, photolithography, and the proper use of the Microfab Lab facility equipment. A mechanical modeling of the movement of the single axis micro-mirror was developed. Piezoelectric actuation was explored but due to malfunction of the piezoelectric materials available, it was not possible. Characterization of the voltage differences across the piezoelectric materials was performed to determine why actuation was not possible. View Paper | View Slides
Porphyrin Thin Film Dielectrics
Advisor: Dr. Jorge Santiago
ABSTRACT: New advances in technology are creating numerous power electronic applications. These applications require a substantial amount of energy that can be produced using capacitor technologies. Novel molecular dielectrics are now being incorporated in capacitors to achieve high energies, and high polarizability.
In this project, different methods of characterizing the molecular chromophore porphyrin were evaluated. The first approach was to spin cast polypropylene doped with Zinc tetraphenylporphyrin (ZnTPP) or zinc diphenylporphyrin (ZnDPP) onto gold sputtered wafers which were to be characterized using a newly constructed capacitance testing device. Analysis of the data produced by this device suggested other potential characterization methods, including the fabrication of Indium Tin Oxide (ITO) Sandwich Cells and the use of microfabrication techniques. Multi-layering porphyin thin film layers was also under experimentation. These methods have set a firm foundation such as providing experimental methods, as well as troubleshooting that will eventually lead to the proper characterization of thin film porphyrin dielectrics. View Paper | View Slides
Dynamometer - The New Activity Monitor
Advisor: Jay N. Zemel
ABSTRACT: Activity monitors are convenient tools for extracting empirical information about a person's physical activity patterns, which may be the source of various health issues. The purpose of the "dynamometer" under development in this research effort is to monitor physical activity that impacts on the emerging issue of childhood obesity, and which also can be related to the development of bone deficiencies such as osteoporosis. The dynamometer consists of a piezoelectric sensor that is embedded into a shoe insole and is connected to a microcontroller for data acquisition and analysis. The analysis of the signal results in information about the magnitude, frequency, and duration of a child's actions such as running and jumping. An amplifier circuit amplifies the signal produced by the sensor. The full implementation of signal processing by the microcontroller was not completed due to time constraints.
A sensor calibrator was designed and fabricated to provide a standard stimulus to test the sensors. The results of testing indicated that although noise was present in the amplified signal, the output was reproducible and clean enough to provide accurate results regarding the sensor response to various forces. View Paper | View Slides