Wilbur L. Walters

Boron-doped carbon nanotube coating for transparent, conducting, flexible photonic devices

Conducting transparent polymer materials were made by applying boron-doped single-walled carbon nanotubes to the surfaces of glass and flexible polyethylene terephthalate film substrates. Optical transmission and sheet resistance measurements showed that the boron-doped coated samples had sheet resistances of ∼7kΩ∕◻ and flat optical transmission of ∼89% for visible light. Temperature and humidity tests showed that the materials remained conductive after nearly 150h of testing. The materials are robust and even maintain their conducting properties after being folded. Fabrication of a simple light emitting device demonstrates usage of the material as a flexible transparent electrode.

Photonic control of flexible structures?application to a free-floating parabolic membrane shell

In this paper, the photonic control of free-floating flexible parabolic shells using photostrictive actuators is investigated. The parabolic shell of revolution is considered to be one of the most difficult geometries among all shell and non-shell structures. Because of this, an approximate way to estimate the dynamic behavior and light-induced control forces for a photostrictive coupled parabolic shell is presented. On the basis of the approximate spherical model, the effects of actuator locations as well as membrane and bending components on the control action are analyzed. The analysis results presented show that the control forces are location dependent. It is also shown that the membrane control action is much more significant than the bending control action. The validation of the approximate model is done by comparing the light-induced control forces of the photostrictive coupled shells obtained using the approximate equivalent spherical shell model and those obtained using the parabolic shell model. From the comparison, it can be concluded that there is only a slight difference between a spherical shell and a parabola for a surface with a focal length to diameter ratio of 1.00 or larger.

Panel - nanotechnology curriculum and research opportunities in undergraduate engineering education

Nanotechnology concepts can be used to entice young students into science and engineering departments. Incorporating these concepts into engineering curricula in a useful fashion can be an expensive proposition. This panel provided a forum for discussion of different approaches and opportunities for including nanotechnology in the undergraduate curriculum at all levels ranging from required freshman courses to elective senior courses

An innovative certification program that prepares undergraduate students for engineering research

Faculty at Jackson State University have developed an In-House Certification program focused on introducing students to scientific and engineering research through hands-on learning experiences. This program is innovative as it is designed specifically for undergraduate research experiences and details a very structured and strategic plan to teach students effective research principles with a measureable incentive. This program is a result of positive results from initiatives funded through the National Science Foundation Nanotechnology for Undergraduate Education program. Students participate in learning characterization techniques, scientific principles and research methods associated with various characterization tools. The program is planned so that students will engage in an analysis technique for 3–6 week duration and then receive a certification for proficiency. Upon completion of the program students participate in mini-projects that are focused in the areas of materials research. The program is a hands-on introduction to materials research that spurs the growth of undergraduates who will continue in meaningful research projects, external internships and ultimately graduate school.

The atmospheric processes associated with the tornadic super-outbreak of April 25 th through 28 th 2011 in relation to global change

A large and violent super-tornado outbreak occurred from April 25th - 28th, 2011, becoming the deadliest 24-hour outbreak in U.S history. According NOAA and the SPC, there were approximately 190 tornadoes reported with 320 deaths within the southern, mid-western and northeastern U.S. In the current study, Arctic sea ice loss affecting the North Atlantic Oscillation, a negative ENSO episode, Gulf of Mexico Sea Surface Temperatures (SSTs) and an unusual shift of dry-line associated with parent mid-latitude cyclone (MCL) are potentially influenced by global change in association with the outbreak and studied using NCEP/NCAR reanalysis, GFS modeling, NCEP/CPC CAMS & NOAA/ESRL/PSD NOAA/AOML/TCHP analysis, and stability parameters obtained from remote sensing. Larger implications state the Arctic sea ice lost reversed upper-level wind distribution and affected major wind systems such as the jet stream. Reduced albedo in the arctic increased solar insolation and shifted the temperature differential between latitudes, potentially perturbing Earths feedback system.

Course Module on Precision Control of Piezoelectric Actuators

Conventional mechanical actuation mechanisms, which have been used to drive nanoscale devices, have the drawback of requiring high power for operation. However, the piezoelectric actuation mechanism offers the advantages of extremely low power consumption. As piezoelectric materials change the practice of engineering and technology, providing undergraduate students with experiences with these materials has become necessary. This paper presents the design of a course module on precision control of piezoelectric actuators for undergraduate students. The course module incorporates lecture, experiment, and problem-based learning as pedagogical tools. Students are given opportunities to work directly with piezoelectric actuators to gain hands-on experience. Students can learn about actuation advantages of the piezoelectric materials along with their control problems. This course module can improve the knowledge of the students on how to design and analyze piezoelectric devices.Copyright

Precision Control of Piezoelectric Actuators With an Inversion-Based Approach

The emphasis in this study is on the compensation of the uncertainties associated with piezoelectric actuators for precise nanomanipulation. A cascade model for creep, hysteresis, and vibrational dynamics of the piezoelectric actuator is proposed. The procedure for identifying the model parameters by experimental data is introduced. The identified model is employed to develop an inverse-based feedforward compensator. This study presents a comprehensive analysis and evaluation of the proposed method. As a result, this proposed approach can lead to a software-compensated platform for precise nanomanipulation.Copyright

Modeling, Control and Application of Piezoelectric Actuators

Nanotechnology is a growing area that educators are interested in attracting students to. Smart materials have become the workhorse in a multitude of nanotechnology. One example is the piezoelectric actuators which are used for nano-positioning in Atomic Force Microscopy (AFM). The majority of today’s engineering and technology students are unaware of the remarkable properties of smart materials as well as their applications in nanotechnology. Therefore, providing students with the knowledge and experience of piezoelectric actuators is the crucial step in integrating nanotechnology into engineering and technology education. One course module has been developed for introducing modeling, control, and application of piezoelectric actuators to undergraduate students at Jackson State University. This module includes classroom lectures, demonstrations, and actual exercises. This paper discusses the development and implementation of the teaching module and provides some initial student feedback. The course module description and covered topics are presented in detailed. The course module presented in this paper can easily and seamlessly be integrated to the existing engineering and technology courses.Copyright

Applications of Smart Materials in Structural Health Monitoring

Structural Health Monitoring (SHM) is an emerging technology devoted to monitoring and assessing of structural health. SHM emerged from the wide field of smart structures and laterally encompasses disciplines such as structural dynamics, materials and structures, non-destructive testing, sensors and actuators, data acquisition, signal processing and possibly much more. To stimulate students’ desire for pursing advanced technologies and prepare them well for their future careers, engineering and technology educators need to dedicate their efforts to educate the students with this emerging technology. At Jackson State University (JSU), three course modules (Smart Materials and Structures, Signals & Data Acquisition Systems, and Lamb Waves Generation & Detection) have been added to the existing courses to help undergraduate students develop hands-on experience for understanding this technology. The course modules do not assume prior knowledge of software and hardware, and they all follow an applied, hands-on approach. These three course modules allow students to gain insight into the SHM as well as to become knowledgeable users of the instrumentation.Copyright

An Introduction to Smart Structure and Its Application in Nanotechnology

The use of smart materials for the control of shape, vibration, and stability of structural systems has become more prevalent in recent years. Nanotechnology is regarded worldwide as the technology of the 21st century. As nanotechnology begins to unfold, smart materials will also play a key role in revolutionizing the productivity of emerging nano applications. To ensure the progress and success of smart-structure technology, engineering and technology educators need to make strong efforts to educate the students. At Jackson State University (JSU), two course modules have been developed and added to existing technology course that have helped undergraduate students develop hands-on experience as well as strengthen students’ foundation in smart materials and structures. The modules consist of lectures and laboratory activities. The lecture materials cover core concepts. The laboratory activities give students hands-on skills with observing, measuring and controlling the behavior of smart structures. The effectiveness of these modules has been assessed. Responses and feedback from students who have taken these modules are very positive.Copyright