TechBot - A Mobile Multitasking 3D Printer

As the use of Additive Manufacturing (AM) is increasing at a staggering rate, it is necessary to come up with new and improved technologies, materials, and processes of AM. One of these ways is to no longer being confined to a dimensioned box to print within, therefore making AM mobile. The new 3D Printer which is underway to construct a mobile system that moves with the help of 4 omni-directional wheels located at the corners of the frame. The system is designed to use the omni-directional wheels for all X and Y axis movement and is, therefore, able to move infinitely in the direction that is chosen by the user. The Z axis of the system is moved by a lead screw attached to a stepper motor and is limited for now. One key feature of the system is also its ability to dispense multiple paste-type materials i.e. food, concrete, solder, and more. This is possible through the use of a fully customized syringe press that is capable of carrying 150mL syringes. This presentation will report the current structure of the system and its preliminary findings

Multi-institutional Design and Manufacturing Practice for a Cutting-Edge Bottle Cap Opener

The Universal Bottle Cap Opener (UBCO) was designed with capability and versatility in mind. This unique project targets to help aid disabled or elderly individuals with the commonly simple task of opening a bottle cap or soda can. UBCO is meant for any additive manufacturing machine to be produced on and is currently the thinnest 3D printable bottle opener with the most versatile uses requiring no support material to be utilized in its fabrication.  UBCO is completely new and different because it is truly universal by definition to every bottle/can that would currently be encountered in the US. No other design is by definition truly universal except to a particular brand name or bottle type. The ergonomic design is meant to reduce fatigue significantly on the hands and wrists of individuals with weaker muscle tissue. UBCU utilizes a single US minted penny, which is installed post printing, as a force absorber to open metal bottle caps without damaging the part or fatigue to the user.  The design, manufacturing and testing stages of this project have been managed by two other institutions other than Tennessee Tech University. Professor Thomas Singer’s team at Sinclair Community College and Professor Eric Wooldridge’s team at Somerset Community College have collaborated with the Tennessee Tech University team to successfully complete this project. The presentation will report the successful completion of the project with the steps from the start to end

*WINNER* NASA Human Exploration Rover Challenge Senior Design Team

This competition challenges high school and college students to construct a vehicle designed to traverse the terrain of another planet. This challenge focuses on testing the design and fabrication, and evaluating skills of each team present. This gives each team present an eye-opening experience in a real-world critical thinking project. Instead of competitors facing an all-out race across difficult terrain as in the past, the challenge now mimics the opportunities, challenges and decision-making that our future planetary explorers will face in interplanetary travel. There are many rules and design regulations set by NASA, which make the race very challenging and competitive. The goals of this year’s project was to create a brand new design that is much lighter, stronger, and more efficient while improving upon the success of the previous year’s rovers. The team plans to put TTU on the top of the leaderboard for the 2019 challenge. Furthermore, the team is planning to win the innovation, featherweight and design competitions. Therefore, the team designed and started to fabricate a completely new and innovative rover. To achieve the teams’ goals, the chassis was designed entirely of titanium with the suspension composed of aluminum tubing and light weight-more efficient pneumatic shocks. These extreme alloys provide the rover with the entire weight to strength ratio necessary to keep the weight to a minimum while retaining enough strength to withstand the harsh race environment and capability of traversing a challenging exoplanetary-like moon landscape

Survivorship and Etiologies of Failure in Single-stage Revision Arthroplasty for Periprosthetic Joint Infection: A Meta-analysis.

IntroductionSingle-stage revision arthroplasty for periprosthetic joint infection (PJI) may yield comparable infection-free survivorship with two-stage revision arthroplasty. It is unclear if the most common mode of failure of single-stage revision arthroplasty is infection or aseptic loosening. In this meta-analysis, we sought to (1) determine survivorship and (2) compare rates of different etiologies of failure of single-stage revision total hip arthroplasty (THA) and total knee arthroplasty (TKA).MethodsPreferred Reporting Items for Systematic Review and Meta-analyses guidelines search was done using search terms for "single stage revision," "exchange arthroplasty," "periprosthetic infection," "PJI," and "single stage." Patient demographics such as age, body mass index, and mean follow-up time were recorded. Overall survivorship and rates of revision surgery were aggregated using a random-effects model. Comparison of septic and aseptic loosening rates was done by risk difference and associated 95% confidence interval (CI) calculation.ResultsTwenty-four studies were identified with 2,062 and 147 single-stage revision THA and TKA procedures performed between 1984 and 2019, respectively. The weighted mean follow-up and age were 69.8 months and 66.3 years, respectively, with 55% men overall. The all-cause revision surgery rate was 11.1% and 11.8% for THA and TKA, respectively. The revision surgery rate secondary to infection and aseptic loosening and associated 95% CI for the risk difference for THA and TKA was 5.5% and 3.3% (-1.7% to 5.0%), and 3% and 8.8% (-11.4% to 2.3%), respectively. Revision surgeries due to instability and fracture combined and mortality rate were both less than 3%.DiscussionSingle-stage revision THA and TKA for PJI demonstrated overall high rates of survivorship, low mortality, and revision surgeries secondary to infection and aseptic loosening to be equivalent. Aseptic loosening after single-stage revision TKA might be higher than in primary TKA. As implant survivorship from infection improves in PJI, surgeons should be aware of aseptic loosening as an equally common mode of failure

Pick and Place Robotic Actuator for Big Area Additive Manufacturing

Oak Ridge National Laboratory’s Manufacturing Demonstration Facility has created a system that works in tandem with an existing large-scale additive manufacturing (AM) system to ‘pick and place’ custom components into a part as it is printed. Large-scale AM leaves a layered surface finish and is typically post-processed through 5-axis CNC machining. Each surface must be accurately recorded into a laser tracking system. This process can be simplified with the use of fiducials, small location indicators placed on the surface of a part. Additionally, the ability to monitor an AM tool via wireless sensors is advantageous to gauge part health as it is fabricated and later used. The ‘pick and place’ system allows thermocouples, fiducials, and other sensors to be accurately placed throughout the tool as it is fabricated. This solution has the potential to reduce time, labor, and cost associated with fabricating, post-processing, and using AM parts.Mechanical Engineerin

The involvement of astrocytes in early-life adversity induced programming of the brain

Early-life adversity (ELA) in the form of stress, inflammation, or malnutrition, can increase the risk of developing psychopathology or cognitive problems in adulthood. The neurobiological substrates underlying this process remain unclear. While neuronal dysfunction and microglial contribution have been studied in this context, only recently the role of astrocytes in early-life programming of the brain has been appreciated. Astrocytes serve many basic roles for brain functioning (e.g., synaptogenesis, glutamate recycling), and are unique in their capacity of sensing and integrating environmental signals, as they are the first cells to encounter signals from the blood, including hormonal changes (e.g., glucocorticoids), immune signals, and nutritional information. Integration of these signals is especially important during early development, and therefore we propose that astrocytes contribute to ELA induced changes in the brain by sensing and integrating environmental signals and by modulating neuronal development and function. Studies in rodents have already shown that ELA can impact astrocytes on the short and long term, however, a critical review of these results is currently lacking. Here, we will discuss the developmental trajectory of astrocytes, their ability to integrate stress, immune, and nutritional signals from the early environment, and we will review how different types of early adversity impact astrocytes