3D Printed Sports Mouthguard

The 3D printed sports mouthguard can be specifically designed to provide exceptional protection and comfort to athletes in any sport. The process by which an athlete undergoes for obtaining their mouthguard requires a substantial amount of time and cost. Introducing 3D printer capabilities into the dental and sporting fields would elicit faster manufacturing time with more economically priced materials. In testing our theory, the initial components of the research consisted of scanning a dental impression cast and transferring the S.T.L. file scan onto the C.A.D. software. The next important step required us to discover which material to wire with the 3D printer so that the first figure could be presented. After the first test material was chosen, we had to manipulate the measurements so that the 3D printer could properly layer the material to form a practical design. We then had to search for materials that adhered to the A.D.A. and the F.D.A.’s requirements for safety as this product is a protective oral device. Although we were unable to provide a fully functional 3D printed sports mouthguard example due to time constraints, we were able to provide a strong foundation for companies which would be willing to invest and apply this research.https://scholarscompass.vcu.edu/capstone/1205/thumbnail.jp

Fatigue strength of additively manufactured polylactide (PLA): effect of raster angle and non-zero mean stresses

As far as polymers are concerned, polylactide (PLA) is certainly the polymeric compound that is most commonly used along with commercial additive manufacturing technologies. In this context, the present paper aims to investigate the influence of manufacturing direction and superimposed static stresses on the fatigue strength of PLA 3D-printed by using the Fused Filament Fabrication technique. This was done not only by generating a large number of new experimental results, but also by re-analysing different data sets taken from the technical literature. As long as the fused deposition modelling technology is used to fabricate, flat on the build-plate, objects of PLA, the obtained results and the performed re-analyses allowed us to come to the following conclusions: (i) the influence of the manufacturing direction can be neglected with little loss of accuracy; (ii) the effect of superimposed static stresses can be quantified and assessed effectively by simply performing the fatigue assessment in terms of maximum stress in the cycle; (iii) if appropriate experiments cannot be run, AM PLA can be designed against fatigue (for a probability of survival larger than 90%) by referring to a unifying design curve having negative inverse slope equal to 5.5 and endurance limit (at =2∙106 cycles to failure) equal to 10% of the material ultimate tensile strength

Evaluation of fit for 3D printed retainers as compared to thermoform retainers

ABSTRACT EVALUATION OF FIT FOR 3D PRINTED RETAINERS AS COMPARED TO THERMOFORM RETAINERS By David Cole, D.M.D. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University Thesis Directors: Eser Tüfekçi, D.D.S., M.S., Ph.D., M.S.H.A. Professor, Department of Orthodontics Sompop Bencharit, D.D.S., M.S., Ph.D. Associate Professor and Director of Digital Dentistry, Department of General Practice Introduction: Despite recent advances in three-dimensional (3D) printing, little information is available on 3D printed retainers Methods: Three reference models were used to fabricate traditional vacuum formed, commercially-available vacuum formed, and 3D printed retainers. For each model, three retainers were made using the three methods (a total of 27 retainers). To determine the trueness, the distances between the intaglio surface of the retainers and the occlusal surface of the reference models were measured using an engineering software. A small difference was indicative of a good fit. Results: Average differences of the traditional vacuum formed retainers ranged from 0.10 to 0.20mm. The commercially-available and 3D printed retainers had a range of 0.10 to 0.30mm and 0.10 to 0.40mm, respectively. Conclusions: The traditional vacuum formed retainers showed the least amount of deviation from the original reference models while the 3D printed retainers showed the greatest deviation

Collagenous Matrix Supported by A 3D-Printed Scaffold for Osteogenic Differentiation of Dental Pulp Cells

Objective A systematic characterization of hybrid scaffolds, fabricated based on combinatorial additive manufacturing technique and freeze-drying method, is presented as a new platform for osteoblastic differentiation of dental pulp cells (DPCs). Methods The scaffolds were consisted of a collagenous matrix embedded in a 3D-printed beta-tricalcium phosphate (β-TCP) as the mineral phase. The developed construct design was intended to achieve mechanical robustness owing to 3D-printed β-TCP scaffold, and biologically active 3D cell culture matrix pertaining to the Collagen extracellular matrix. The β-TCP precursor formulations were investigated for their flow-ability at various temperatures, which optimized for fabrication of 3D printed scaffolds with interconnected porosity. The hybrid constructs were characterized by 3D laser scanning microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and compressive strength testing. Results The in vitro characterization of scaffolds revealed that the hybrid β-TCP/Collagen constructs offer superior DPCs proliferation and alkaline phosphatase (ALP) activity compared to the 3D-printed β-TCP scaffold over three weeks. Moreover, it was found that the incorporation of TCP into the Collagen matrix improves the ALP activity. Significance The presented results converge to suggest the developed 3D-printed β-TCP/Collagen hybrid constructs as a new platform for osteoblastic differentiation of DPCs for craniomaxillofacial bone regeneration

Characterisation of Cryogenic Material Properties of 3D-Printed Superconducting Niobium using a 3D Lumped Element Microwave Cavity

We present an experimental characterisation of the electrical properties of 3D-printed Niobium. The study was performed by inserting a 3D-printed Nb post inside an Aluminium cylindrical cavity, forming a 3D lumped element re-entrant microwave cavity resonator. The resonator was cooled to temperatures below the critical temperature of Niobium (9.25K) and then Aluminium (1.2K), while measuring the quality factors of the electromagnetic resonances. This was then compared with finite element analysis of the cavity and a measurement of the same cavity with an Aluminium post of similar dimensions and frequency, to extract the surface resistance of the Niobium post. The 3D-printed Niobium exhibited a transition to the superconducting state at a similar temperature to the regular Niobium, as well as a surface resistance of $3.1\times10^{-4}$ $\Omega$. This value was comparable to many samples of traditionally machined Niobium previously studied without specialised surface treatment. Furthermore, this study demonstrates a simple new method for characterizing the material properties of a relatively small and geometrically simple sample of superconductor, which could be easily applied to other materials, particularly 3D-printed materials. Further research and development in additive manufacturing may see the application of 3D-printed Niobium in not only superconducting cavity designs, but in the innovative technology of the future.Comment: 5 pages, 4 figure

3D Printed Soft Robotic Hand

Soft robotics is an emerging industry, largely dominated by companies which hand mold their actuators. Our team set out to design an entirely 3D printed soft robotic hand, powered by a pneumatic control system which will prove both the capabilities of soft robots and those of 3D printing. Through research, computer aided design, finite element analysis, and experimental testing, a functioning actuator was created capable of a deflection of 2.17” at a maximum pressure input of 15 psi. The single actuator was expanded into a 4 finger gripper and the design was printed and assembled. The created prototype was ultimately able to lift both a 100-gram apple and a 4-gram pill, proving its functionality in two prominent industries: pharmaceutical and food packing

3D Printed Embedded Force Sensors

Additive Manufacturing and 3D printing has opened the door to an endless amount of opportunities, including recent advances in conductive and resistive circuit printing. Taking advantage of these new technologies, we have designed a 3D printed insole with embedded plantar pressure sensor arrays. The customizable aspect of 3D printing allowed us to uniquely design a multitude of sensors. With the use of a dual extrusion printer we were able to produce a model that printed both the resistive circuit and complete insole simultaneously. These distinctive technologies have given us the capability to capture valuable pressure data from the sole of the foot. Analog signals sent from the pressure sensor arrays are received and processed through an attached multiplexer designed specifically for this application. The signal is then digitized and transmitted over the SPI transfer protocol to a processor and wirelessly communicated, via Bluetooth Low Energy, to a mobile android device to allow the user to easily record and interpret the array\u27s pressure data in real-time. The android device houses a pressure mapping view to show the gradient of force throughout the insole. With the capabilities of this insole we have provided an avenue for physicians and physical therapists to gather quantifiable insight into their patient\u27s progression throughout the rehabilitation process. With more intelligent and personalized data the applications of this technology are countless.https://scholarscompass.vcu.edu/capstone/1147/thumbnail.jp

3D-printed Acoustic Directional Couplers

Acoustic Directional Couplers permit separation of forward and reverse sound pressure waves. This separation opens the way to traceable precision acoustic reflection measurements. In order to span the audio frequency range, multiple couplers will be required, as each operates over a frequency range of slightly more than one octave. To reach 20kHz or above requires vary small, mechanically precise construction. We achieve this by 3D printing techniques. We manufactured two otherwise-identical couplers, one made with a powder-type 3D printer with photopolymer support structure, the other made with an ABS-filament thermoplastic-type 3D printer. We compare the measured acoustic performance of these two couplers. The wavelength of sound at 20 kHz is comparable to that encountered at a microwave frequency of 18 GHz. We expect to be able to fabricate couplers that reach 55 kHz where the wavelength is 6 mm, corresponding to a frequency of 50 GHz in the electromagnetic spectrum

3D Printed Ear Canal Model

A multi-material ear canal model was designed and created from CT scans of an actual patient. This ear canal model serves as a training model for trainees, surgeons and doctors to develop a better understanding of the anatomy and physiology of the ear by physically looking, touching and testing the model. The major task taken was to establish and identify the area of interest provided with the files of medical scans by using 3D Slicer. The files were then converted to a stereolithographic (STL) file where it was able to be edited for smoothing in programs such as Meshmixer or MeshLab in order to 3D print a high quality model that could be used effectively. An operate model was obtained that satisfied the given need for ideal surgical training purposes; where the design is composed of a two piece multi-material model – the outer ear is flexible and the inner ear canal is rigid. A replicated membrane is attached to the end of the inner ear canal to represent the tympanic membrane. Lastly, the entire model is mounted on a magnetic stand that has a 360° rotation for trainees or doctors to adjust for ideal positioning. This project was very informative; while being educated on the current health needs, we were also able to serve the local physicians by producing the requested devices. The ear canal model is ready to use and can be used for a pre-surgery mechanism to allow for resourceful practice. Trainees in particular who are just beginning to learn can take advantages of using this model. Common type of surgery performed includes Otitis Media with effusion (OME), which is the accumulation of fluid buildup, often in the middle of the ear, with no sign or other symptoms of an ear infection. Roughly about two million cases of otitis media with effusion occur annually in the United Stateshttps://scholarscompass.vcu.edu/capstone/1216/thumbnail.jp