The objective of this project, which builds on work done by a previous team, is to produce a device that aids in research on dynamic loading of the knee joint, with a view to developing improved surgical techniques. The device facilitates analysis of how mechanical behavior varies between diseased and healthy joints. A primary requirement for the device is to collect and store data about two degrees of freedom in the knee, measuring such parameters as flexion, extension, internal rotation, and external rotation. As a mechanical system it is important to create a realistic movement incorporating the patella tendon, which was achieved by developing a pulley system and a nondestructive tendon clamp. As knee movement is simulated, each sensor collects data for research analysis.

The goal of this project is to design, build, and test a robust tablet with an application for controlling a robot unit onboard a naval vessel. The final design has a ruggedized iPad Mini using the Triton’s Link robot-control application, which sends a signal to the robot telling it where to go and how to get there. The application contains control test procedures and monitors output data such as the robot speed, direction, and force of collision. Because security is paramount, a code generator was developed to provide a code to input into the robot application. To ruggedize the tablet, a 3-D shell case was designed and printed for the iPad Mini. The case is held together using HeliCoils and screws, contains thick foam for insulation and shock proofing, and is fitted with a watertight gasket. The case was developed to survive water, wind, and fluctuating temperatures, and to ensure that the iPad Mini still functions after hitting the deck from a great height. This ruggedized tablet and robot-control application could be a cheaper and more technologically advanced alternative to current U.S. Navy systems, which are old and expensive to replace.

Nasogastric tubes are hollow thermoplastic tubes used to deliver nutrition to the stomach of patients who cannot ingest food orally. A common medical malpractice event is the introduction via these tubes of liquid into the respiratory tract instead of the stomach, which can result in fluid aspiration that can lead to patient harm or death. Current standard of practice verifies tube placement in a hospital via a chest X-ray or stomach acid pH test. While these procedures are effective, they are not conducive to repeat verification and require the skills of medical professionals.
The goal of the project is to develop a cost-efficient and easy-to-use device that informs the user when the tube has been placed in the stomach, not the airway. The device is small enough for use within existing tubes and can withstand the corrosive gastric environment for up to 30 days. This design uses an open circuit that is closed by ions present in the acidic fluid of the stomach. The closure of the circuit results in a differential voltage signal that provides the user with a “safe to feed” message.

The design team was charged with finding an overlooked energy source and harvesting it to extract usable electric power. The team chose the magnetic field created by overhead power distribution lines, which yielded enough energy to power small electronics such as a Wi-Fi hotspot, a communications repeater, a phone, or a light that could be easily deployed in rural areas. The team built a device that clamps onto a 14kV power line. Using a current transformer, the device is able to induce usable alternating current in a circuit that is then rectified, smoothed, and regulated out to direct current via a secondary circuit. It is then able to provide 12 watts of power for the user’s consumption. The device is equipped with a metering chip and a radio frequency communications module managed by a microcontroller. This circuitry relays the appropriate metrics to the user. The device information is transmitted to a computer equipped with a communications receiver module and displayed on a custom graphical user interface. Data made available to the user reflects voltage, current, and power levels being consumed. The harvested power is available to the user through multiple outlets, including a USB plug and general two-prong/barrel DC connectors.

The project sponsor, a crossbow manufacturer, asked the team to design a new entry-level crossbow made 80 percent from pre-existing parts. The sponsor also specified use of its injection-molding plant to use up spare capacity and to create a carbon-fiber-reinforced thermoplastic component. Design focused on plastic part design and mold capability restrictions to ensure that designed parts could be made at the sponsor’s production facility. Injection molding limitations required the team to research methods that would allow multiple pieces to be connected while maintaining the structural integrity of the bow. One of the difficulties with injection molding, especially with a carbon fiber material, is that a relatively uniform thickness is required throughout the design. This required the insertion of coring and ribbing features to the design to reduce the range between maximum and minimum thicknesses. The resulting crossbow is lighter in weight with a better center of gravity – that is, closer to the trigger – than the previous model.

Advances in small, nearly conformal wireless electronics have created a need for compatible flexible antennas. Potential applications include radio-frequency identification tags, unmanned aerial vehicle communication, radio technology, mobile phones, and sensors for cars and aircraft. The goal of this project is to use an inkjet printer with conductive ink to print functional antennas. Materials for this technology are readily available and antennas can be produced quickly and inexpensively. The team conducted a design of experiments to determine the best method for printing a working antenna by testing different printers, inks, substrates, and printing methods. Conductive ink was used with standard inkjet printers to create a two-dimensional antenna print. Size and flexibility were key design parameters.

The purpose of this project is to design, analyze, and fabricate an autonomous stabilizing helicopter landing platform. The prototype designed and built by the team is scaled to represent ship size (littoral combat ship USS Coronado), ship motion, and helicopter size. The prototype includes a scale model of the 20-foot-wide helicopter platform that remains stabilized through constant adjustment of the platform level with respect to the simulated ship motion. Using platform-mounted inertial sensors, the platform can adjust its pitch and roll in the opposing direction of the ship’s motion. Because the helicopter platform is not located at the center of the ship, calculations were done based upon the full-scale center of mass dimensions of the USS Coronado. These results were scaled to 10 percent and are implemented in the design of the prototype system. The scale model landing platform is attached to a base that mechanically simulates the ship’s pitch and roll motion. A stabilized helicopter landing platform mitigates the operational limits induced by the pitch and roll of the ship by autonomously tilting to cancel ship pitch and roll angles. This prototype system will be used by Boeing to demonstrate the complexities of landing helicopters on ships at sea.

The project sponsor asked the team to design a wearable wireless body-area network – a Fitbit is an example of a wireless body-area network – that enables the user to monitor critical body functions by smartphone. The device, worn around the chest, contains three sensors: a combined accelerometer-gyroscope programmed to detect falls, and two sensors to monitor heart rate. Upon detecting a fall, the device’s smartphone app notifies the user’s designated contact. One heart rate sensor uses LEDs and a photodiode to measure changes in light intensity as it bounces off the skin and into the receptor; the other is a three-lead electrocardiogram. The user wears three stickers on the chest, from which wires carrying the heart’s intrinsic electrical signals are fed into the device. The signal is conditioned and amplified, and the reading sent to the user’s smartphone app via a Bluetooth transmitter.

The team’s objective is to develop an autonomous platform that can map an indoor single-floor environment in two dimensions. The design integrates an autopilot with a system-on-a-chip board. The platform carries a camera to capture images or video for virtual reality interfacing. Video captured and stored by the platform is provided to the user after mapping is complete, and the user can experience remotely a simulation of the indoor environment via a virtual reality headset. Measurements of the environment allow the platform to autonomously maneuver and generate a building floor plan accessible by the user. Applications include realtors creating virtual reality experiences for customers.

The team was asked to design an omnidirectional vehicle test bed and laboratory to enable faster and more cost-effective testing of autonomous vehicle navigation algorithms. Lab users can load algorithms into a microcomputer mounted on the vehicle, which is fitted with reflectors that allow infrared cameras to track its location. Algorithmic efficiency can be determined by comparing data from cameras with data from algorithms. An Xbox Kinect, inertial measurement unit, and six ultrasonic sensors provide information for the algorithm. Navigation calculations are performed on a Raspberry Pi 2, and an Arduino Zero is used to interface with sensors. Movable obstacles are placed in the testing area to allow users to custom build test scenarios. The test bed and laboratory have been designed with future expansion in mind. Subsequent projects could involve simultaneous use of multiple vehicles. The omnidirectional capability of the vehicle allows land- and space-based vehicle navigation algorithms to be tested.