Design

Research Samples

Students: Louisa A. Avellar (UCB), Mircea Badescu, Stewart Sherrit, Yoseph Bar-Cohen, and Wayne Zimmerman of Caltech
Research Project Title: Pneumatic Sample Acquisition and Transfer System
Location: NASA's Jet Propulsion Laboratory, Pasadena, California

 

Abstract:
http://www.techbriefs.com/component/content/article/3-ntb/tech-briefs/mechanics-and-machinery/19562-pneumatic-sample-acquisition-and-transfer-system

 

Student:  Tim K. Chan
Professor/Sponsor:  Professor Alice Agogino
Mentor:  Euiyoung Kim

Research Project Title:  Prototyping of Wearable Notification and Tracking Device with Bluetooth Connectivity

 

Abstract: 

We introduce the use of a wearable device for notification under distracting environment, for instance, in a rave or a conference. During the research, we came up with two models - centralized and ad-hoc. In the centralized model, the wearable device is aimed at finding people who present in the same event/venue whilst the ad-hoc model, we targeted one-to-one location tracking without the use of pre-existing network. Centralized model will be used during a populated event like a rave where it's virtually unable for people to hear their phone ring of vibrate. Ad-hoc model will be used in situations like parents keeping track on their kids in an amusement park.

 

Student:  Serena Chang

Professor/Sponsor:  Professor Alice Agogino

Mentor:  Euiyoung Kim

Research Project Title:  Activity Comparisons Over Digital Artifact By Their Physical And Emotional

Distance: User’s Attention Level Upon Primary and Secondary Digital Artifacts

 

Abstract:

Although a majority of the Internet of Things devices have been introduced in the market places, the adoption rate of these new devices hasn’t been quite inspiring due the lack of motivation that enables users to stick with them around over a long-term time frame. Many introduced IoT devices have short life cycles and people simply go back to their traditional devices as primary interaction. Based on our research, the laptop and the smartphone are the most dominant devices regardless of the introduction of the new IoT devices. Thus, this research focuses on the usages of these two devices to explore users different attention levels upon primary and secondary digital artifacts and to compare their physical and emotional distances.

 

A prototyping segment of this research further explores the concept of emotional distance between users and devices in physical spaces. Indicator spectrums allow users to visually indicate their emotional state to other co-located individuals with whom they are not directly interacting, at the opposite corner of a coffee shop, for instance.   Once the indicators are digitized and connected, the “mood” of a particular physical space can be assessed by IoT developers.

 

Student: Stephanie Chang
Professor/Sponsor: Professor Alice Agogino
Mentor: Euiyoung Kim
Research Project Title: Establishing User Spaces in Medical Exoskeleton

 

Abstract:
As exoskeleton technology matures and becomes increasingly commercialized, the user spectrum of such technologies need to be identified and studied. This project examines exoskeleton technology from a human centric standpoint, establishing a comprehensive range of users for such products. In order to establish context to create a spectrum of exoskeleton users, literature was collected and reviewed to discover what exoskeleton researchers identify as their target users. The functionality of different types of exoskeletons are also identified and categorized and then matched up to potential user needs from different personas. From the literature review, different categorical spectrums are established to represent the range of users who would make use of exoskeleton technologies. Examples of spectrums include age, physical age, familiarity with advance technology, etc. In addition, further research into socially sustainable assistive technologies are identified and matched up to corresponding user personas and needs.

 

Student: Galen Elias
Professor/Sponsor: Professor Reza Alam
Research Project Title: Load Shedding Trends of Submerged Rigid Bodies Subject to Monochromatic Water Waves
Research Areas:  Design, Fluids, Ocean Engineering

 

Abstract:
Wave Energy Converters are devices which convert the renewable energy in ocean waves to electricity. A submerged pressure differential WEC uses a rigid absorber to split a wave’s orbital, creating a pressure gradient which drives a generator. One of the engineering challenges of WECs is to make the device robust enough to handle extreme ocean conditions, during which waves can carry upwards of 30 times more power than usual.1 As such, we looked into ways to reduce the load the device would experience under extreme conditions. Due to the high buoyancy of the device and the high-energy cost of increasing its depth, we focused mainly on the effect of changing the device’s shape. In particular, we analyzed trends in front-to-back hole placement and trends in wall thickness between holes within a constant footprint.

 

Student: Hunter Garnier
Professor/Sponsor: Professor Alice Agogino
Mentor: Drew Sabelhaus
Research Project Title: ULTRA Spine

 

Abstract:

Due to its complexity, the ULTRA Spine Quadruped robot assembly process is extremely time consuming and tedious, making it difficult to rapid-prototype new designs. This research report describes the process of designing an elastic lattice that would replace the cables and springs that traditionally tensioned the robot. In order to create the final design, several concepts were explored, a tension test was completed on silicon rubber to find its elastic modulus, and various lattice shapes were assessed. The final design decreased the assembly time of the ULTRA Spine from three hours to approximately 7 minutes, improved the symmetry and vertebrae alignment of the robot, and will reduce the design, manufacturing and assembly process of future spine prototypes.

 

Additionally, a test setup to measure ground forces on the prototype’s feet is described in this report. Previously, the two main motions of the spine—torsion and bending—were seen qualitatively but not expressed quantitatively. By placing a load cell under each foot of the quadruped prototype, the forces under each could be measured while the spine underwent torsion or bending. However, this test setup was unsuccessful and did not produce convincing data.

 

Future plans for this project include designing a higher quality test setup to measure ground reaction forces as well as a higher fidelity spine prototype.

 

Student: Jimmy Huang

Professor/Sponsor: Professor Dennis Lieu
Sub Area: Biomechanical Engineering
Research Project Title: Novel Silicone-Compatible Pressure Transducer Tips and Calibration Device for Simulation Torso Design

 

Abstract:
This paper details the progress made during the Spring semester of 2015 in Professor Dennis Lieu's Ballistics Impact Lab, and is a continuation of "Silicone Curing Behavior and Updated Method of Simulation Torso Construction" from Fall 2014.

 

Less-lethal projectiles such as rubber and wooden bullets are commonly used by law enforcement for the purpose of incapacitating targets with minimum injury. However, these non-penetrating injuries can still cause severe internal damage and even death. With understandable concern, investigation by Professor Dennis K. Lieu and his Ballistics Impact Lab researchers has been underway since 2003. Originally intended to model the response of the human torso utilizing silicone, the scope of this project has extended to include the design of safer less-lethal projectiles.

 

Recently, the group has been experiencing difficulties producing a homogeneous and consistent silicone simulation torso with embedded pressure transducer. One main focus of this paper is the design and manufacturing of several new, oil-tight pressure transducer tips. This includes our continued exploration of silicone-compatible materials as well as a new sensor housing design. Another area of focus is the design and manufacturing of a calibration device for new pressure transducers before they are embedded into a silicone torso. This information will hopefully be useful for new Ballistics Impact Lab researchers and for those in similar laboratories or using the same silicone material.

 

Student:  Jimmy Huang
Professor/Sponsor:  Professor Dennis Lieu
Research Project Title:  The Effect of Varying Transducer Tip Thicknesses on Peak Internal Pressures

Subarea:  Biomechanical Engineering

 

Abstract:

This paper details the progress made during the Fall semester of 2015 in Professor Dennis Lieu's Ballistics Impact Lab, and is a continuation of  "Novel Silicone-Compatible Pressure Transducer Tips for Simulation Torso Design" from Spring 2015.

 

Less-lethal projectiles such as rubber and wooden bullets are commonly used by law enforcement for the purpose of incapacitating targets with minimum injury. However, these non- penetrating injuries can still cause severe internal damage and death. With understandable concern, investigation by Professor Dennis K. Lieu and his Ballistics Lab researchers has been underway since 2003. Originally intended to model the response of the human torso utilizing silicone, the scope of this project has extended to include the design of safer less-lethal projectiles.

 

Most recently, the group has been focusing its efforts towards improving the design and manufacturing method for the model torso with an embedded pressure transducer. This semester, our team set out to understand the effect of varying transducer tip thicknesses on peak internal pressures. This endeavor involved manufacturing a brand new model torso and subsequently testing different torsos with distinct tip designs. During the process we also designed and manufactured  a novel calibration apparatus. This apparatus allowed us to translate peak voltages to internal pressures experienced by the model torso, and can help us to individually calibrate each sensor and tip design in the future. Finally, the lab also revisited the concept of healing the silicone in an effort to recycle spent silicone torso blocks.

 

Student:  Jimmy Huang
Professor/Sponsor:  Professor Dennis Lieu
Research Project Title:  New Silicone Tissue Stimulant and Pressure Transducer Setup for

Less Lethal Ballistics Applications

 

Abstract: 

Less-lethal projectiles such as rubber and wooden bullets are commonly used by law enforcement for the purpose of incapacitating targets with minimum injury. However, these non- penetrating injuries can still cause severe internal damage and death. With understandable concern, investigation by Professor Dennis K. Lieu and his Ballistics Lab researchers has been underway since 2003. Originally intended to model the response of the human torso utilizing silicone, the scope of this project has extended to include the design of safer less-lethal projectiles. This paper details the progress made during the Spring semester of 2016 in Professor Dennis Lieu's Ballistics Impact Lab, and is a continuation of " The Effect of Varying Transducer Tip Thicknesses on Peak Internal Pressures" from Fall 2015. Most recently, the group has been focusing its efforts towards improving the design and manufacturing method for the model torso with an embedded pressure transducer. This semester, our team initially focused on exploring the concept of healing silicone in an effort to recycle old silicone torso blocks.  Further along, the group set out to benchmark new silicone tissue stimulants as well as new pressure transducer alternatives for more robust less lethal ballistics setups.


Student: Stefan Klein
Professor/Sponsor: Professor Dennis Lieu
Mentor: Daniel Talancon
Sub Area: Mechatronics Design
Research Project Title: INSTAR - Inertial Storage and Recovery

 

Abstract:
INSTAR (Inertial Storage and Recover) is a mechanical engineering research group headed by Professor Lieu and recent PhD graduate Daniel Talancon. Our research surrounds a flywheel energy storage device for electric vehicle applications. In the past semester working with INSTAR, I completed several tasks related to the preparation of our go-kart test platform for our Cal Day exhibit and to the rebuilding of our flywheel energy storage device. To prepare our go-kart, I flushed and bled our brake system, which returned it to working condition, but also led to me discovering a leak on the master cylinder, which will be repaired by the next Cal Day. Furthermore, I disassembled our inertial simulation test setup, which consists of two large steel disks to simulate the inertia of the kart and two magnetic brakes to simulate the mechanical brakes of the kart. I then reassembled our battery packs and reinstalled the seat and wheels. In preparation for Cal Day, where we would, for the first time, have the final flywheel on display, a polycarbonate shield in between the flywheel and driver had to be designed and machined. I oversaw and helped several of the team's freshmen in this task. Finally, there was a significant electronics error in our kart, which caused the startup of our motor controllers to fail randomly. I traced the error to the pedal assembly of the kart, whose angular encoders tended to slip, causing a non-zero braking and throttle signal to be inputted into the motor controllers, causing the startup to fail. Regrettably, I was unable to find a permanent fix for the problem before the exhibition on Cal Day, but a pedal assembly redesign is planned to stop the problem at its source. On Cal Day, I helped present our project to prospective students and parents, which has generated some interest in new students who have already contacted our lab. Finally, I began the process of rebuilding the flywheel's rotor. For this task I rebuilt the electric motor's rotor, which had to have a new set of neodymium magnets epoxied to it and was then wrapped in kevlar for strength. Overall, my participation in INSTAR has helped further my education in design and mechatronics and helped keep the INSTAR project rolling even with the recent graduation of our graduate student, Daniel.

Students: Andrew Kooker and Casey Duckering
Professor/Sponsor: Professor Robert Full
Mentor: Chen Li
Sub Area: Mechatronics
Research Project Title: Micro-Robot with Ambulating and Jumping Abilities: A modification of the Biomimetic Millisystems Lab robotics for testing and analysis on animal locomotion processes

 

Abstract:
The goal of this project is to create micro-robots that can simulate standard insect/animal motions such as walking and running while being able to jump over encountered obstacles. The simulation of jumping mechanisms found in nature on fully mechanical robots can be used to better understand how and why they are used. Designs for robots can be created by understanding the dynamic effects of a jumping ability on motion when encountering obstacles, and simulating them effectively.

 

The initial step of our project dealt with simulating the simple motion of jumping on micro-robots that could already walk and run. It was important to analyze different methods of jumping from quick actuation to elastic storage; for the ability to continuously jump on command, the method of quick actuation seemed ideal. We created an actuating hinge mechanism in SolidWorks and developed the basic skeletal models for the robot in AutoCAD. By using rapid-prototyping techniques such as 3D printing and laser cutting, we were able to quickly bring these computer renditions to life for physical testing. We integrated mechanical and electrical components like gearing systems and microcontrollers for actuation, and combined these assemblies with the base-skeleton of our robot. After writing software to test the system, we analyzed the effectiveness of our design based on the robot performance and developed a second iteration of the robot accordingly.

 

Throughout the design process, we were required to focus on key decisions like material choice, specific component purchases, and overall integration methods. We developed many iterations of software to efficiently test the robots, and made many design changes to the jumping mechanism and robot body itself. We were also able to learn principles of re-design by taking already-developed robotic components from the Biomimetic Millisystems Lab, and further modifying them to fit our needs.

We compared the effectiveness of our designs among iterations, and mapped out performance goals for future generations of the robots. We plan to continue modifying current robot designs and creating custom completely new designs for jumping-specific robots in the future. We also hope to continue the development of unique electronic components and software to seamlessly integrate with our mechanical robots.

 

Student:  Leslie Leung

Professor/Sponsor:  Professor Dennis Lieu

Research Project Title:  The design and initial testing of flashlight-inspired battery tubes

 

Abstract: 

The INertial STorage And Recovery (INSTAR) vehicle combines the use of battery packs and a flywheel as its energy storing and supplying components.  The subject of this research centers on a new impact-resistant, fire-resistant, and well-ventilated design for battery packs consisting of rechargeable lithium ion cells.  Inspired by the packaging of a flashlight, the design aims to achieve an ease of assembly and disassembly for replacement of individual cells.  Housed in standard-sized aluminum tubing, six cells are preloaded by stainless steel springs fixed against polyether ether ketone (PEEK) end caps by a stainless steel bevel head screw.  Current flows from one battery tube to others via copper bus bars connecting adjacent tubes together.  A prototype consisting of two tubes was constructed as a proof of concept.  Static testing with a voltmeter returned expected voltage readings for a single tube, two tubes in series, and two tubes in parallel.  A setup scheme for dynamic testing is proposed for future study to determine the safe operating frequency range and the robustness of electrical connections during motion.  The design of the casing for the complete battery packs and the battery packs’ electrical connections with the vehicle’s battery management system (BMS) are also proposed.

 

Student:  Kevin Li
Professor/Sponsor:  Professor Alice Agogino
Mentor:  Lee-Huang Chen
Research Project Title:  Design, Manufacturing and Testing of Tensegrity V3 Robot

Design

 

Abstract: 

With recent advances in reusable rocketry and planetary discoveries, space exploration has come to the forefront of scientific news and research. My role in the Berkeley Emergent Space Tensegrities Lab has been to assist in developing the Tensegrity Spherical Robot V3, a robust yet compliant robotic system designed to take advantage of the unique characteristics of tensegrity structures. In doing this, I was involved in all aspects of the engineering process including hardware and software design, component manufacturing and component testing. In designing and manufacturing hardware, emphasis was placed on the ease, speed and cost of manufacturing and assembly in order to streamline the rapid iterative design process. In software design, an intuitive control scheme was developed for the twenty-four independent motors as well as a text interface for switching between manual control of individual motors and preset step sequences. Finally, in component testing, a physical drop test was developed to drop the Tensegrity V3 from heights of up to six feet, which helped confirm the compliance of the system, the strength of individual components and the accuracy of simulations.

 

Student:  Carlin Liao

Professor/Sponsor:  Professor Alice Agogino

Mentor:  Julia Kramer

Research Project Title:  'The Design Exchange' Ontology Team

 

Abstract:

The work of the ontology team of the Design Exchange is primarily qualitative, focusing on categorizing and analyzing various methods in design thinking. Within the pools of "Data Gathering," "Ideation," "Analysis & Synthesis," "Building/Prototyping," and "Communications," we have collected process descriptions for close to three hundred design methods such as Dot Voting, Visual Brainstorming, and Video Ethnography. From these processes, our team has identified more than 100 skills shared across multiple methods that may be relevant to design thinking as a professional endeavor. Following the completion of our master skill list will be the construction of a questionnaire designed to refine and verify our assessment of common design skills by surveying the professional design community, in particular those making the decision on which designers to hire.


Student: Chengming Liu
Professor/Sponsor: Professor Liwei Lin
Mentor: Casey Glick
Subarea: Fluid Mechanics
Research Project Title: Single-Layer Microfluidic Current Source via Optofluidic Lithography

 

Abstract

 

Student:  Kevin Li
Professor/Sponsor:  Professor Alice Agogino
Mentor:  Lee-Huang Chen

Research Project Title:  Design and Manufacturing of Soft Spherical Tensegrity Robot
 

Abstract:

With recent advances in reusable rocketry and planetary discoveries, space exploration has come to the forefront of scientific news and research. My role in the Berkeley Emergent Space Tensegrities Lab has been to assist in developing TT-4, the fourth version of the spherical tensegrity robot, a robust yet compliant robotic system designed to take advantage of the unique load-bearing characteristics of tensegrity structures. The goal for this prototype was to validate scaling of the spherical tensegrity design from the smaller TT-3, so the prototype is completely passive with the circuit boards designed specifically for drop testing. Key steps included manufacturing of hardware components and circuit boards, followed by final assembly of the TT-4 drop test prototype. Following that, a full drop test was designed and characterized to test the capabilities of the much larger TT-4. Hardware components included aluminum rods and endcaps, plastic and FDM module housings, extensions springs and fishing line. The circuit board was built for the drop testing and contained only a Teensy 3.2 microprocessor, 9-DOF absolute IMU, XBee wireless chip and voltage regulator. With a fully assembled board attached to the central payload of TT-4 as well as another attached to a module, a comparison of the G-forces between the payload and a rigid element of the robot can be made in order to validate the load-distributing characteristics of the tensegrity structure as well as the safety of a potential payload. With the hardware and software components of the TT-4 drop test prototype completed, the final step will be completing the drop test at a later date.

 

Student: Ryan Liu
Professor/Sponsor: Professor Dennis Lieu
Research Project Title: Protocol for Ballistics Lab Data Collection

 

Abstract:
In an effort to reduce long-term sustained injury from non-lethal weaponry, research was undertaken to investigate a new type of kinetic energy projectile. The projectile is similar in shape and energy transfer to currently used commercial non-lethal projectiles, but is made of a highly deformable, hyper-elastic, modified silicon rubber. Tests were conducted analytically using ABAQUS (FEA) and experimentally inside the UC Berkeley ballistics test lab. This report outlines the protocol necessary to perform ballistics lab work, which may be useful for both new ballistics lab researchers and for researchers at other laboratories alike.

 

Student: Hannah Ling
Professor/Sponsor: Professor Dennis Lieu
Mentor: John Madura
Research Project Title: Design/Manufacturing of Oil Circulation System for Electric Vehicle
Research Areas:  Design, Manufacturing

 

Abstract:
The Inertial Storage And Recovery(INSTAR) kart uses an electric flywheel as part of a hybrid system to efficiently store energy from regenerative braking. The flywheel can store up to 100 kJ of energy by spinning at speeds up to 20,000 RPM. An adequate lubrication system is crucial to the safety and durability of the flywheel because it reduces wear when spinning the flywheel at high speeds. The design and components of the previous lubrication system were flawed and did not effectively lubricate the flywheel. The following report documents the features of the previous circulation system and illustrates its flaws, as well as explaining the design, part selection, and manufacturing process of a new reservoir and circulation system. Although the system is not fully assembled, the currently installed components have already improved the effectiveness of the lubrication system allowing for a greater range in the speed of flywheel testing.


Student: Nicholas Anthony Renda
Professor/Sponsor: Professor Dennis Lieu
Mentor: Daniel Talancon
Research Project Title: INSTAR RP-1: Development and Testing of an Electric Vehicle KERS Platform

 

Abstract:
My research this semester focused on creating a robust mounting solution for a flywheel-based energy storage system as part of the INertial STorage And Recovery (INSTAR) Lab. The flywheel is part of a Kinetic Energy Recovery System (KERS) on an electric go-kart, for the purpose of regenerative braking. The flywheel mount is designed to support the flywheel under extreme driving loads (cornering, braking, accelerating), while simultaneously damping vibrations through the use of rubber isolators. The flywheel spins up to 25,000 rpm, so special care is taken to isolate all vibrations between it and the go-kart chassis.

 

The mount is made of 6061-T6 aluminum billet, and was designed to be manufactured almost entirely on a waterjet machine through the use of 2d profile parts. Bolt holes were postdrilled on a drill press to ensure tight tolerances. Rubber isolators embedded in the mounting plate damp vibrations and react shear loads to the chassis. A containment system was also designed to account for special load cases, such as flywheel seizure. In this load case, the rotating steel mass stops in less than 2 rotations due to debris in the bearing or an external impact. This imparts a massive torque on the mount, which begins to rotate and shears through the rubber isolators. It then comes in contact with the containment brackets, which are designed to take the load of a seizure impact without failing.

 

The go-kart was tested without the flywheel to ensure proper function of all other systems, including batteries, steering, brakes, motors, pedals, and electronics. INSTAR met its goal of a fully functional kart by Cal Day, having debugged code and designed new batteries and pedals to accomplish this task. The vehicle systems were then thoroughly tested to ensure sturdiness during multiple cycles of high-intensity accelerating and braking.

 

Student:  Nick Renda
Professor/Sponsor:  Professor Dennis Lieu
Research Project Title:  Load and Safety Considerations in the Design of Flywheel Kinetic Energy Recovery Systems for Electric Vehicles

 

Abstract: 

Flywheel technology has novel applications in electric vehicles as the core component of a kinetic energy recovery system. Flywheels have quick charge and discharge rates, and can be used to recapture the energy that is generally lost using current regenerative braking technology or traditional friction brakes. One challenge to implementing these systems is mechanically connecting the flywheel to the vehicle chassis. This project focuses on the development of a robust flywheel mounting system that minimizes vibration transmission from the chassis, reacts loads under extreme driving conditions, and protects the driver in the event of a catastrophic failure.


Student: Hale Reynolds
Course Project: ME 102B
Research Project Title: "Smart" Energy Harvesting and Usage as Applied to a Bicycle Light

Abstract:
For this project, a standard battery powered Light Emitting Diode (LED) bicycle light was modified, allowing it to harvest and store all the energy required for its use.

When normally operated, the bicycle light used for this project requires four AA batteries, located in a compartment just behind the circuit board holding the LEDs, and normally operates for around nine hours before the batteries must be replaced. The batteries were removed and replaced with a coin-sized rechargeable Lithium-Ion Battery (LIB), and circuitry governing the storage and usage of the generated electricity. (The LIB and circuit take up the same space as the four AA batteries.)

 

To generate electricity from the normal usage of the bicycle, very strong magnets (Neodymium magnets with residual flux density of 14.7 KGs) were mechanically fixed to the spokes in a similar fashion to the typical attachment of bicycle speedometer magnets. Then a tightly wound, fine copper wire coil was attached to the bicycle fork at the location where the magnets attached to the spokes would pass. As the magnets pass the copper coil, their magnetic field induces a potential difference across the coil ends. This voltage potential then drives the flow of current through wires run along the bicycle frame to the battery compartment. Before reaching the battery, the current must pass through series of four diodes arranged as a full-wave rectifier to ensure that regardless of the direction of the magnet rotation and regardless of the magnet polarity orientation, the electricity serves to charge the battery.

 

To govern the usage of the charge stored in the battery, a simple control circuit was designed. For daytime operation of the bicycle, when it is light out, the generator charges the battery. Because no additional light is needed when it is bright out, the battery stores its charge and does not power the LEDs. For night riding or in other dark conditions, it is desired that the LEDs be powered to illuminate the cyclist's way. This photosensitive functionality was achieved using two transistors, an operational amplifier, a photosensor, and a series of resistors.

 

The circuit governing the use of the battery's charge is a small photosensor interfaced with an operational amplifier which was then connected to a CMOS Inverter (composed of the two transistors, one N-Channel and one P-Channel). If the output from the photosensor is high (light is incident upon it), this signal is amplified by the operational amplifier and the inverter allows no current to pass from the battery to the LEDs of the bicycle light. If the output from the photosensor is low (no light is incident upon it), this signal is still amplified by the operational amplifier, but if it is low enough, the inverter allows all the required current for full LED brightness to pass to the LEDs of the bicycle light. The resistors are used in balancing the operational amplifier, effectively calibrating the system. With the proper resistor combination, the circuit was calibrated to have the inverter transition between states at the proper, practical light intensities for day and night bicycling.

 

Key Points:
Through the use of this device, rather than replace four AA batteries after every nine hours of use, a smaller battery may be used to store energy generated from the normal use of the bicycle, and does not need replacing. It was found that during normal usage of the bicycle, 40% of the energy consumed from full-brightness bicycle-light use could be generated. This means that when it is bright out, and the bicycle light is off, the battery is easily charged, while at night the battery life is greatly extended. Although the energy produced by this device comes from the energy supplied by the rider, because there is no contact between moving components, and because the power generated is relatively small, there is no noticeable drag on the wheel due to energy generation. Also, in-terms of cost, the total cost of this project was much less than for a high-end bicycle light.

 

Student:  Patrick Savidge
Professor/Sponsor:  Professor Dennis Lieu
Research Project Title:  Calibration of Piezoresistive Pressure Transducer Embedded in Silicone

 

Abstract: 

The Impact Lab at UC Berkeley is in development on non-lethal bullets. Currently the lab is developing bullets made from Medical Grade Silicone Gel. These bullets are shoot at a silicone torso and the internal pressure felt by the torso is recorded. This paper outlines the process used and results obtained from calibrating the Piezoresistive Pressure sensor embedded in the silicone torso. The sensor was mounted in a small piston cylinder device and Medical Grade Silicone Gel was cured around the sensor. Various weights were applied to the device to vary the pressure applied and the output voltage from the sensor was recorded. These voltages were then applied to data obtained within the Impact Lab to determine the pressure experienced under impact testing.

 

Student:  Ellande Tang
Professor/Sponsor:  Professor Alice Agongino
Mentor:  Lee-Huang Chen

Research Project Title:  Hardware Improvements to Tensegrity robots and a Potential Alternative Actuator for Linear Motion
 

Abstract:

Tensegrity robots have tremendous potential for space exploration due to their deformability and compliance. Their innate impact resistance allows them to traverse rough or precipitous terrain with substantially reduced risk. However, tensegrity robots are hampered by their complex geometry, which makes them difficult to assemble and visualize on paper, as well as their primary method of actuation, which requires linear motion. This report examines the improvement of tensegrity assembly methods through improved rod end attachment hardware and re-evaluates the performance of a novel type of linear actuator inspired by twisting cable actuators as well as the double helix geometry of DNA.  The new endcaps were designed to interact more favorably with the single elastic lattice of the TT-4 mini tensegrity robot.  Incorporating grommets into the elastic prevents them from slipping off the rod ends as in previous designs. Additionally, the use dowel pins as wire guides improves manufacturability and allows effective end caps to be made without 3d-printing. Lastly, the introduction of threaded holes simultaneously allows for the lattice to be secured and to attach actuation cables without the need for tying knots. Combined with the other changes, this reduces tensegrity assembly time to under 5 minutes while addressing a number of the previous flaws of the design, improving durability and robustness.

 

The DNA actuator shows promise as an effective linear actuator. With the construction of a new, lower friction testing assembly, the characteristics of the actuator can be determined with more accuracy. The actuator in its current for displays potential as a practical linear actuator, as it displays interesting properties. Among them is the property of the required torque for actuation depending not upon load but upon the present number of rotations. These properties merit further analysis of the DNA actuator with different materials and geometric configurations.


Students: Aliakbar Toghyan and Borna Dehghani
Professor/Sponsor: Professor Alice Agogino
Mentor: Kyunam Kim
Sub Area: Controls
Research Project Title: Tensegrity Robot

 

Abstract:

Soft robotics and tensegrities are the new chapters to the world of robotics. The term "Tensegrity" is a combination of the words "Tensile" and "Integrity", and it represents any structure consisting of elements that are only under tension or compression. The main objective of the Tensegrity research was to come up with a relatively low-cost but appropriate representative of NASA's future explorer SUPERball. The purpose of making the early prototype was the initial approval of the control algorithm used for the movement of the robot, since the process of making the actual prototype in NASA is overly expensive and time consuming.

 

The robot consists of six rods that are connected by 24 elastic elements and it is formed into a sphere like configuration. The sphere would be able to roll by means of actuating the elastic components. As a team member I focused on designing a control algorithm for the robot. Based on simulation of the robot in Matlab, I found the optimized control algorithm for certain movements. Afterwards, I implemented the control system in the prototype and made sure that the robot had the desired motion.

Students: Lee Weinstein and Martin Cacan
Lab: Berkeley Manufacturing Institute
Research Project Title: Battery-Replacement Scale Energy Harvesting From HVAC Flows

 

Abstract:
The objective of the project is to create an energy scavenging device that produces over 100 μW of power in air flows of 2-5 m/s. These operating conditions are characteristic of HVAC systems, and the power output would be sufficient to run a low-power wireless sensor node at ~1% duty cycle.

The approach we have pursued is using a cylindrical obstacle inside an HVAC flow to trip vortex shedding. A fin attached to a piezoelectric bender vibrates and harvests energy as a result of an oscillatory pressure differential caused by periodic vortex shedding off of the obstacle.

An image and a few more details are available on our lab website: http://ame.berkeley.edu/

Student: Sean Zhu
Professor/Sponsor: Professor Alice Agogino
Mentor: Cesar Torres
Research Project Title: Design Exchange UI

 

Abstract

 

Student: Zea Wang
Professor/Sponsor: Professor Tarek Zohdi
Mentor: Maxwell Micali
Research Project Title: Variable Nozzle

 

Abstract:
As additive printing is gaining in popularity and increasing its uses, it is important to minimize build time while maintaining resolution throughout the part. A variable nozzle is able to accomplish this by changing the extrusion diameter while printing. A variable nozzle introduces additional flexibility in the 3D printing process. Not only will this make additive manufacturing more efficient, it will allow for artists to explore a new feature, further expanding the abilities 3D printing.

 

Our team's design features the use of a mechanical iris mechanism to vary the diameter of the nozzle. This allows for the cross section of the mechanism to remain relatively circular as the diameter varies while printing. The 3D Potterbot, a ceramic printer, was chosen in order focus on the mechanical design without interference of heat and phase transitions in the material. In testing, the mechanical iris was successful in changing the size of the extruded material from 6mm to 20mm continuously. Problems came about as the iris reached the smaller diameters due to the bunching of the rubber liner between the clay and the mechanism. High pressure is also applied to the mechanism from the clay during extrusion making the rotation of the iris and therefore the changing of the diameter difficult.

 

This semester has been focused on testing the nozzle on a ceramics printer and documenting problems when implementing a variable nozzle. The second priority is finding ways of automating the entire system with a motor. The next steps of this research will focus mainly on the software needed when a variable nozzle is introduced. This includes changes in the slicer as well as the feed and print rates of the 3D printer in order to minimize the build time and provide the best possible resolution.