The ability to eat our meals how and when we want is often taken for granted, but is not a reality for some with limited upper body mobility. Current haptic sensory inputs for autonomous robotic feeding systems are inconvenient and expensive. We propose using GelSight, a fingertip tactile sensor capable of providing rich haptic feedback. Built with silicone and 3D printed parts, GelSight uses a camera to track a grid of dots embedded in the silicone and estimate forces. GelSight is accurate and inexpensive to manufacture and overcomes many of the limitations of currently available and previously tested options. Based on laboratory tests and feedback from potential users we continue to improve our hardware and software, seeking to generalize our solution to any food.

This project aims to influence the next generation of flying robots by first studying how moths use multi-sensory information to increase their agility. These different types of multi-sensory information include visual- and touch-based feedback, which are influenced by forces such as those from flapping wings and changes in body posture (which affect a moth’s inertial distribution). In addition, flying insects are known to control orientation via torques arising from at least three distinct affordances: by varying aerodynamic center of pressure, by changing body posture to alter center of mass location, and by swinging body segments or limbs to harness inertial torques. We hypothesize that these sources of control are integrated in parallel to increase robustness and agility, are weighted according to behavioral context, and are tuned to body morphological parameters. To investigate this flight behavior, we first built a test apparatus to apply rapid pitch movements to a tethered flying moth, Manduca sexta, while having a minimal effect on a moth’s inertia and natural flight patterns. This system allows us to measure the torque exerted by the moth’s flight forces and body movement. Closing the loop between measured torque and applied movement enables control of the forces experienced by the moth. Projected video is used to simulate a changing environment and create a haptic-type interface for the moths. The video can provide a visual experience to either match the mechanosensory experience or provide sensory conflict (i.e. a mixed reality environment). The next engineering challenge is to design and build a system to electronically control and monitor the motion of the moth. After this, cameras and sensors will be used to record data that will contribute to a more realistic understanding of how the principles of animal flight can be used in robotics.

Robotics combines machining and artificial intelligence to create real world humanoid models for task automation and industrial applications. We have designed an in-house robot prototype having microprocessor controlled motion. The robot has lasers for eyes and has a position sensor with camera attached. We designed the gear box, track assembly and robot parts and have written software to control the motion of the robot. The robot is good model for Roomba like vacuum cleaner. We create random walls using Monte Carlo simulations and used vector directed motion to control its motion for avoiding these random walls that the robot encounters to simulate real world experience. We have also studied robotic arm kinematics, using matrix algebra and trigonometry to help design a robot arm that we can rotate or translate to any point in three -dimensional space. We study both forward and reverse kinematics and have written software for the arm motion. Our studies provide an elegant educational platform for studies of robot motion along with simulating real-world experience.

Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) have great potentials in biomedical research and can be used extensively in drug screening and heart simulations. To understand the cardiomyocytes, we need to perform functional analysis on these muscle cells. Therefore, we need a simple, controllable, yet biocompatible and high throughput tool to measure the cellular traction force. At the Sniadecki Lab, we are developing a new technique to measure the force generation of hiPSC-CM: dotted traction force microscopy platform. To create the platform, fluorescent proteins were first absorbed to a dotted polydimethylsiloxane (PDMS) negative and stamped onto a polyvinyl alcohol film. The film was then transferred to a soft PDMS substrate and subsequently dissolved using phosphate buffered saline solution while the patterned fluorescent proteins stained the substrate. Since the stiffness of the soft PDMS substrate is known, the force generation of the cardiomyocytes can be calculated in real time by optically tracking the deformation of the fluorescent dots. Currently, we are able to manufacture the platform with high fidelity and uniform alignment with a production time of less than 2 hours. Moreover, the cardiomyocytes can fully spread out to their in vivo state on the substrate which ensures the force measurement is valid and accurate. Potentially, this method is not limited to cardiomyocyte research and can be applied to study the interaction between force generation and cell performance of other cells. We are also exploring the possibility of automated manufacture and integration with 96-well to enable mass production.

Women and people of color are underrepresented in classrooms as both instructors and students, as well as in the field of physics. A lack of diversity limits the ideas that evolve and creates disadvantages for systemically nondominant groups. The goal of this research is to understand how we can make students feel more empowered to change the culture in physics. Students in introductory, calculus-based physics classes from both a two-year college and a four-year university participated in a similar equity unit, which focused on increasing awareness of the systemic marginalization of women and people of color in physics. At the end of the unit students brainstormed how to raise awareness of, and then ultimately remove, this inequity. We analyzed and coded students’ responses using key words and phrases coinciding with similar ideas. The themes were tested for reliability by the authors who addressed discrepancies through discussion, after independently categorizing these responses. Students from both populations (two-year and four-year colleges) concluded that learning about their own bias and having intentional conversations about equity issues are both important steps in physics for changing societal structures. One theme unique to the two-year college setting was to develop coping strategies that combat inequities in physics. Future work will involve acquiring more data from different student populations and using that data to better support students in various physics learning contexts. By following students’ suggestions from the equity unit, we can take action to create an inclusive and diverse physics culture.

A DNA screening tool is being developed to allow rapid DNA testing in the field to identify endangered species of timber and wildlife. This work describes the design and testing of a chip holder and a gasket to improve the performance of this tool in the field with the consideration of usability, manufacturability and functional constraints. The chip holder is composed of a cradle with a hinge, two glass chips and one gasket. This chipset contains all reagents required to perform a DNA amplification test and features microfabricated heaters with electrical contacts to drive this reaction. Prototypes for chip holders with different hinge thickness and designs were fabricated in polypropylene using a Lulzbot Taz-6 3D printer with an Aerostruder tool head. The hinges were tested manually to ensure that the design parameters provided a stable joint. Gaskets were created by pouring Smooth-On Liquid Silicone Oomoo 25 into 3D printed molds. Silicone gaskets and chips undergo thermal testing on hot plate at 95 °C for 25 minutes to test if adhesion changes. Leakage testing for the gaskets is done through placing 0.2 g of water between gasket and chip and pressure are added between the chips to check water loss. We found the optimal material for gasket under DNA testing condition is Liquid Silicone Oomoo 25, and the best adhesive for the gasket and glass chip is silicone based adhesive GE Silicone II. Future work would be finding a more efficient method to produce the gasket, apply adhesives and adhere the gasket and glass chip. For the chip holder, the next step would be choosing the manufacturer, and select the specific polypropylene for mass production.

Manipulating airflow over aerodynamic surfaces with plasma, compressed air jets and textured surfaces has become an area of intense aeronautical research and international competition in the last few years. Electrohydrodynamic (EHD) thrusters or plasma actuators have been demonstrated as remarkable devices for separation control and lift enhancement. The application of EHD thrusters to an aerial vehicle can drastically reduce the power consumption, weight and response time of mechanical controls. The focus of the present work is to determine the performance of a full-scale aircraft wing with an integrated corona discharge driven EHD thruster numerically. The numerical model is carried out by coupling the interactions between fluid mechanics and electrostatics. The study has been conducted on an augmented NACA 0012 airfoil with trailing edge flaps at a Reynolds number of 160,000 (10m/s). The EHD induced jet delays separation while lengthening and flattening the separation region. Preliminary results show that the actuator has increased the moment on the airfoil by 50% which helps in better maneuverability. The numerical results are compared with the experimental wind tunnel results. These findings can favor a strong design of a new generation energy-efficient aircrafts

Fiber-reinforced composites are advanced materials that combine polymeric matrices with fibers to achieve low densities along with high strengths and moduli. These properties make composites invaluable to industries that rely on materials with high strength-to-weight ratios, such as aviation and aerospace. This contribution discusses the structural design of the Hyperloop Prototype built by the University of Washington’s team competing in the SpaceX Hyperloop Competition. As the Structures’ team lead, my work has centered around designing a reinforced sandwich panel c-channel design, for the upcoming fourth competition, to optimize the total structural weight to 16lbs respect to the third competition design’s weight of 60lbs. I then analyzed and optimized this design using 1D beam analysis scripts written in MATLAB as well as 2D composite shell analysis in Femap and Hypersizer software to validate SpaceX’s structural stiffness and strength requirements. The structures team conducted an extensive testing campaign to capture flexural properties and identify limit loads of the design. This campaign included three-point-bend tests to capture sandwich panel properties and insert hardpoint testing to validate performance of the mechanical joints between the primary structure and propulsion, stability and braking modules. Finally, with the support of Boeing composite production advisors, the team manufactured prototype composite structures making use of advanced industry procedures including use of FlexCore, carbon puck hardpoints and autoclave cure cycles. This work serves as a critical example of composite material technology application to student-lead design projects as well as the engineering knowledge that can be developed outside of the traditional classroom setting through research and independent studies.

Whispering Gallery Mode (WGM) sensors have unprecedented sensitivity in the optical detection of label-free biomolecules. These sensors can detect surface adsorption and have been used to detect single molecule adsorption and interaction processes. By observing resonance shifts during molecular interactions, WGM sensors can characterize a molecule’s surface adsorption. The goal of this project is to develop a robust WGM dip sensor array controlled by a three-axis stage in order to perform high-throughput characterization of peptide binding and adsorption within a 96-well plate format. The peak of spectral absorbance is the WGM resonance, and as this changes with surface adsorption we measured a spectral shift. Using this spectral shift in combination with the known concentration of our peptide species, we determined binding kinetics. The WGM sensor was used to characterize different peptide sequences to further understand the effects of peptide mutations on binding kinetics. A single microsphere resonator was used as proof of principle and will eventually be adapted to an array of eight WGM microsphere resonators to generate large amounts of data. This high throughput approach will provide the much needed large amount of quality data that is necessary for the development and adaptation of machine learning and applied statistical analysis algorithms toward the eventual development of artificial intelligence platforms in material science. The project is supported by NSF-DMREF through the Materials Genome Initiative.

Asteroid sample return has potential to impact research and how humans collect resources, but sample return missions remain prohibitively expensive and complex. We propose a device to retrieve a preexisting sample container from the surface of an asteroid or other extraterrestrial body, focusing on simplicity, repeatability, and reliability. Taking inspiration from a classical design, the bear trap, we created a functional 3D printed prototype, which is mechanical and capable of capturing a 1.5x15 in cylinder resting on a flat surface. Consideration was given to potential rocky terrain or an awkwardly positioned return container, and to sealing the sample container to prevent contamination upon return to earth. Future prototypes will be constructed from stronger, lighter weight materials and will be further developed during active field tests on debris at a penetrator impact site in Eastern Washington.

The study of the behavior of multiple agents, specifically human and machine, in a dynamic environment is challenging due to the unpredictable individual behaviors. Humans will naturally formulate beliefs about the machine’s behavior, which would directly affect their future decisions. Our research aims to develop a framework for the study of human-machine dynamic interactions. With the imperfect information humans and machines have about each other and their environment, a game-theoretic approach was done to study the natural model of their interactions. We derive theoretical models for steady-state (i.e. equilibrium) and transient (i.e. learning) behaviors of humans interacting with other agents (humans and machines). We also design experiments to validate our theory. A haptic testbench, in the shape of a robotic arm, is used as a dynamic simulation platform for studying the trajectories of the human/machine interaction, allowing us to study both theoretically and experimentally. The robotic arm has a position control system that supports a wide variety of human/machine experiments. The user is provided with visual and haptic feedback, which allows for experiments to be designed to study the sensorimotor learning processes. The robotic arm is built using direct-drive brushless motors, force sensors, an open-source ODrive motor controller, and an arm lever. The motor firmware is designed in C/C++, and integrated with a user-interface in Python. With the wide variety of potential applications, we hope our research will give insights into the different natures of human motion and be a fundamental platform for technological breakthroughs in the medical field.

Manufacturing workers are often subjected to many rigorous and repetitive shoulder and arm motions, usually leading to shoulder injuries. Assessing the likelihood of an injury before it occurs and adjusting practices accordingly can keep the individual from the severe pain that shoulder injuries can cause. This research focuses on creating such a predictive model to warn individuals before they sustain an injury. I created a mathmatical model to assess critical positions that would cause the most stress in the shoulder joint. A Kinect sensor locates the arm joints in space and my Matlab code calculates the expected reaction forces in the shoulder. My current results focus on single, static positions defined by common industry working positions. Future work will focus on dynamic positions and comparing the results from the mathematical model with biological indicators to determine if this predictive model is indicative of injury.

Efforts to engineer flying micro-robots (~50mg) are motivated by their potential advantages relative to larger robots, such as greater deployment numbers at the same cost. There are significant developments in flapping wing robots at insect-scale; however, little advancement has been made in the development of robots with ionic actuation using electrohydrodynamic (EHD) thrust. This thrust is generated through the ionization of air particles and momentum transfer of these positive ions with neutral air molecules. EHD thrusters have used collector grids and emitter wires to generate a thrust for controlled flight. In this research, we design and fabricate a 1.8 x 2.5 cm micro-thruster that weighs a total of 43 mg including the carbon fiber collector grid, four blue tempered steel emitters, and eight fiber optic glass tubes. This robot is hand-assembled using a laser fabricated external fixture. Electrodes of the robot are fabricated using a laser based system. The whole robot takes a total of 20 minutes to assemble. Emitters are supplied with a high voltage (~2.5kV) using a bundle of 51-gauge insulated copper wires. Similar wire is used for grounding the collector grid. A parametric study is carried out to optimize the physical parameters of the robot. Experiments performed in this research show that the thrust generated is larger than the weight of the robot.