The Mighty Sawyer

A recreational Sawyer robot that plays cornhole against a human opponent.

Visit this github page for more information

Ice Cube Simulation

The dynamics of an ice cube sliding on a coveyer belt and landing on the ground was simulated in Python using the Google Collaboratory application. The simulation was fabricated by manually computing Euler Lagrange equations to determine the trajectories for each phase of the simulation.

For more information please visit this link for more information and access to the source code.

youBot Mobile Manipulator

A simulated youBot mobile manipulator from KUKA was programmed to plan and follow a desired trajectory which entailed picking up a cube from its initial configuration and delivering it to its final configuration. The software application V-REP simulator was used to load a simulated scene of the youBot and cube and data in the form of CSV files were fed into the application to visualize the trajectory.

Please visit this github page for more information and access to the source code

Spiked Leg Harness

Inspired by fashion-tech engineer Anouk Wipprecht and anthropologist Edward T Hall, this project is an avante-garde wearable fashion tech device that is meant to bridge the gap between STEM and the creative arts. The device is a leg harness with spikes or quills extruding outward and able to detect incoming objects and move accordingly. This project is meant to redefine the user's social space by giving the user the freedom and power to control his/her surrounding environment.

Visit this github page to find the source code, circuit diagrams, and in depth information about the project. Visit this github page to access the 3d printed/CAD files.

Note:this project is in its final stages of completion. A demo video will be recorded and uploaded soon.

Don't Run Out of Oxygen

Inspired by the indie game Lovers in a Dangerous Spacetime, this game was designed and created by a small team using the game engine Unity and Photoshop. Check out this video for gameplay and check out this git repository for an executable to run the game. Read below for more details.

About

Don't Run Out of Oxygen is a cooperative 4 player game focused on manning a tactical submarine under the sea to complete objectives and explore surrounding regions. The storyline is centered around a group of marine biologists who discovered that the ocean wildlife has been corrupted by the non-physical entity known as global warming. These marine biologists decide to take matters into their own hands, going on an expedition to cleanse the sea and stop this infectious spread.

Each player is controlling a marine biologist within a submarine with the goal of activating a series of purifiers. The submarine has multiple stations in which each player may attach themselves to. Additionally, the submarine is equipped with an oxygen and pressure level bar, indicating its current state. Along the way, corrupted sea life will attack the submarine, depleting its oxygen level. If oxygen is completely depleted, the players have failed their mission. To win, players must be working with each other by occasionally switching stations to aid each other in dire situations.

Gameplay

The game is meant to be played using an xbox or ps4 controller, although the tutorial in the beginning of the game references xbox controller inputs. The game supports up to 4 players/controllers, and will load up characters based on the number of controllers connected. Each character is unique to the player.

Game begins with a tutorial explaining controls and objectives, which initially entails moving around the submarine and laching onto stations. Each station performs a specific action. There are a total of 6 stations that comprise of 4 turret stations, 1 steering station, and 1 map station. Each of the turret stations control a single turret capable of firing bullets at incoming enemies. The steering station allows the player to manuever the submarine underwater, and the map station allows all players to view a minimap of the surrounding area. The primary goal of the player steering the submarine is to attach the submarine to each purifier while dodging enemies. Oxygen within the submarine is constantly depleting at a steady rate, and under low pressure this rate increases. Additionally, there are enemies attacking the submarine which will further deplete oxygen. When the submarine is attached to a purifier, it takes some time for the submarine to fully activate it. During this time interval, a swarm of enemies will rush towards the submarine to attempt to halt this process. If players are able to successfully activate the purifier before oxygen runs out, oxygen is replenished as a reward and players get to choose between a power up. The power ups include turret, steering, and map enhancements. Along the way there will be oxygen bubbles that the player steering the submarine can collect to replenish a small portion of oxygen and these oxygen bubbles may form an arrow to indicate the direction to travel. Once all purifiers are activated, players enter a final boss fight.

Art

All art, with the exception of a single background used during gameplay, is custom made via Photoshop and inspired by Lovers in a Dangerous Spacetime. Samples of art created are shown below.

Fluidic Fabric Muscle Sheets

Project Synopsis

This project explores the mechanical behaviors of soft actuators known as fluidic fabric muscle sheets (FFMS). FFMS are comprised of two layers of fabric housing hollow elastic tubing that are capable of actuation along a 2D or 3D plane. The actuation is driven by fluid transmission via imposed strains from the tubing to the fabric sheets. The key is to deliver enough fluid pressure to the FFMS in order to impose axial stresses that result in tube elongation. This form of actuation is especially appealing to soft robotics applications due to its simple and low cost construction while able to perform a variety of tasks. This project demonstrates the feasibility of fabricating these actuators as well as the possible integration with garments and smart clothing.

For resources such as code and design documents, refer to this git repository . This project was assisted and inspired by the publication "Fluidic Fabric Muscle Sheets for Wearable and Soft Robotics" by Mengjia Zhu.

Fabrication

The fabrication of FFMS can be categorized into 3 stages - stitching, threading, and wrinkling. These methods along with design considerations are outlined below.

Stitching

To house the soft tubing, stitches are needed to create conduits in which the tubing can be later threaded into. These conduits must be narrow enough to radially constrain the tubing, forcing the tubing to axially expand when pressurized. Before stitching these conduits, several design considerations were established. In order to prevent radial expansion, non-stretchable cotton fabric was used in tandem with straight side stitches. Both small and large fabric sizes of 50mm and 350mm were used to demonstrate effectiveness. To stitch the fabric together, high strength nylon thread was used due to its ability to withstand high amounts of pressure without tearing. Stitching the conduits was performed on two layers of identically sized fabric using a commercially available sewing machine. The size of the conduits was determined by the tubing type. In order to effectively constrain the tubing, it was found via trial and error that the ideal conduit size for housing the soft rubber tubing was the tube’s OD plus 4mm.

Threading

Threading the tubing in between the fabric conduits was unexpectedly difficult. The difficulties from this task arise from the properties of both the fabric and tubing used. Soft rubber tubing was used due to its low elastic modulus, allowing it to deform under high pressure. The tradeoff was with the tube’s high friction coefficient, which made threading difficult within narrow conduits of non-stretchable fabric. It was found via trial and error that sewing a conduit width with 4mm of extra space with respect to the tubing OD was the minimum width that allowed for proper threading while being able to radially constrain the tubing. Tubing was threaded using a steel rod with the tubing attached to its end. The steel rod was first threaded through the conduits, followed by the soft tubing.

Wrinkling

For the fabric to axially lengthen alongside the tubing, wrinkling was performed to reduce fabric length to 50% of its original length. This was done by holding the fabric stationary and pulling on one end of the threaded tubing. Once the fabric was wrinkled, excess tubing from the ends were removed.

Mechanical Design

The first prototype was curated using a fabric length of 50mm and tube OD of 3mm in order to demonstrate a working concept. The following video demonstrates this.

After achieving a working concept, a larger FFMS structure was designed within the application of smart clothing. This concept was driven by creating clothing that is able to adapt or respond to environmental stimuli. The design entails a custom wire structure acting as a harness and support system for the FFMS. The FFMS acts as a collar that is able to extend upwards once pressurized. Although the user is able to control the source of pressure using a handheld syringe, a solenoid valve is used to regulate fluid flow to the FFMS. The valve is toggled to turn on and off within a set time period using an Arduino Uno. An illustration of the mechanical design is presented below.

As fluid from the 30ml syringe is expelled, fluid flows from the syringe through the two rigid rubber tubings that are secured with tube fittings. Fluid then travels into a 1 inlet, 2 outlet manifold. The purpose of this manifold is to allow the capability to pressurize multiple FFMS segments, with each segment corresponding to a single manifold. For testing purposes, only one port was tested and the latter was sealed. The non-sealed outlet port is attached to rigid tubing, which is then attached to a series of threaded connectors and the solenoid valve. The final threaded connector is directly attached to a tube fitting where the soft tubing housed by the FFMS is directly attached to. Additional stitches were sewn on both ends of the FFMS to allow for structural support and to drive the linear actuation of the fabric.

Electrical Design

The following circuit was constructed to control 2 solenoid valves using a 4 channel relay module.

A brief script was also written to toggle the valves on and off over a set time period. This demonstrates the versatility of behavior that can be achieved when integrating with the FFMS (i.e. using an external sensor and toggle valves based on information received).

Results

The constructed apparatus is shown below.

The required pressure range to drive the actuation was determined by taking into account the elastic modulus of the tubing, operating range of strains, and cross sectional area of tubing and fluid. These pressure values influenced the type of syringe that can be used to power the actuator. The minimum required pressure to reach full actuation was determined to be approximately 600kPa and was calculated using the following formula.

Although actuation did occur for a brief moment, joint connections began leaking and depressurizing the actuator. This was most likely due to the constant high pressure being exerted on non-actuating elements. It is important to note that some components were from different manufacturers and thus were not an exact fit with one another. Teflon tape was used as an extra precaution to secure the joints, and although it did work well for a brief moment, leakage did pass through the tape. Although actuation didn’t perform as expected, the solenoid valve was able to control the flow of fluid. In order to improve this outcome, proper securing tools such as o-rings and hose clamps will be used to tighten every joint. To further prove this notion, a separate test was performed on two 50mm FFMS attached directly to each manifold outlet, as shown below.

In this construction, all non-actuating elements were retrieved from the same manufacturer, tube fittings used were specifically compatible for the rigid tubing models, and hose clamps were used to tighten the connections from the manifold. Under these conditions, actuation did occur and no leakage was observed. Future steps towards improving the construction of the apparatus will mimic these observed conditions.