Mechanical Engineering Commons^™

Pneumatic Latched Demultiplexer Circuit For Controlling Multi-Actuator Soft Robots, Arsh Noor Amin

Master’s Theses

This thesis presents a novel method for controlling multi-actuator soft robots using pneumatic latched demultiplexer circuits implemented with monolithic membrane valves. The pneumatic circuits are designed to address the problems of heavy dependence on hard electrical components and lack of feasible multi-actuator soft robotic systems that limit the potential applications of soft robotics. The proposed pneumatic demultiplexers reduce the number of solenoid valves and electrical components required to drive soft robotic systems, making soft robot control mechanisms more compliant, scalable, and versatile. The thesis demonstrates the design, fabrication, and testing of 4-bit and n-bit pneumatic demultiplexer circuits that can control …

Design Of A Proprioceptive Actuator Utilizing A Cycloidal Gearbox, Craig John Kimball

Master's Theses

Legged robotics creates the demand for high torque compact actuators able to develop high instantaneous torque. Proprioceptive actuator design theory is a design theory that removes the need for a torque feedback device and relies on the stiffness in the leg for absorbing the high Ground Impact Forces created by walking locomotion. It utilizes a high torque density motor paired with a gearbox with a high gear ratio for torque multiplication. Previously work has been done to design a proprioceptive actuator design that utilizes a planetary gearbox to create a modular low-cost actuator for legged robotics. The purpose of this …

Polyvinyl Chloride Gels: Theoretical Modeling Of Their Actuation Mechanism And Characterization Of Their Properties, Zachary Frank

UNLV Theses, Dissertations, Professional Papers, and Capstones

Polyvinyl chloride (PVC) gels are an electroactive polymer smart material which has been considered in a variety of actuator applications. Their large deformation, fast response rates, optical transparency, and soft nature has made them a key area of interest in fields ranging from soft robotics to optics. PVC gels are made from PVC mixed with large quantities of plasticizer, such as dibutyl adipate (DBA). When a voltage is applied, the gel experiences an “anodophilic” deformation (in which it moves preferentially towards the anode). This unique characteristic is the result of a charge buildup near the anode surface, which creates electromechanical …

Inverted Fluorescence Microscope, Matthew B. Pfeiffer, Spencer George Hann, Thomas James Eggenberger, Trevor Lee Blythe

Mechanical Engineering

Team F13 is composed of Trevor Blythe, Spencer Hann, Matthew Pfeiffer, and Thomas Eggenberger. We are all majoring in mechanical engineering and in our final year of study here at Cal Poly San Luis Obispo. This project is a continuation of a 2019-2020 senior project. The previous team designed and built a functioning inverted fluorescence microscope (IFM) from scratch. This device was created as a lab tool for undergraduate students to be able to perform experiments on microfluidic devices constructed in Cal Poly’s Microfabrication Laboratory. Although substantially functional, several design constraints had not yet been met. Our team has improved …

Polymeric Impulsive Actuation Mechanisms: Development, Characterization, And Modeling, Yongjin Kim

Doctoral Dissertations

Recent advances in the field of biomedical and life-sciences are increasingly demanding more life-like actuation with higher degrees of freedom in motion at small scales. Many researchers have developed various solutions to satisfy these emerging requirements. In many cases, new solutions are made possible with the development of novel polymeric actuators. Advances in polymeric actuation not only addressed problems concerning low degree of freedom in motion, large system size, and bio-incompatibility associated with conventional actuators, but also led to the discovery of novel applications, which were previously unattainable with conventional engineered systems. This dissertation focuses on developing novel actuation mechanisms …

Dual-Axis Solar Tracker, Alazone Smith

All Undergraduate Projects

The global energy crisis and continued supporting evidence of global climate change have begun to shift the world economies towards solutions that solve both challenges. Solar power has become one of the most recognizable and popularized renewable energy methods to date. In comparison to other photovoltaic systems, this project demonstrates the performance advantages of a dual-axis solar tracker. It also addressing its viability on a non-commercial scale. The objective was to improve upon previous solar tracker projects at Central Washington University by adding another axis to the system. This system implements both an actuator and a stepper motor to examine …

Theoretical And Experimental Investigation On The Multiple Shape Memory Ionic Polymer-Metal Composite Actuator, Qi Shen

UNLV Theses, Dissertations, Professional Papers, and Capstones

Development of biomimetic actuators has been an essential motivation in the study of smart materials. However, few materials are capable of controlling complex twisting and bending deformations simultaneously or separately using a dynamic control system. The ionic polymer-metal composite (IPMC) is an emerging smart material in actuation and sensing applications, such as biomimetic robotics, advanced medical devices and human affinity applications. Here, we report a Multiple Shape Memory Ionic Polymer-Metal Composite (MSM-IPMC) actuator having multiple-shape memory effect, and is able to perform complex motion by two external inputs, electrical and thermal. Prior to the development of this type of actuator, …

Water Jet Cutting Head Actuator, Jacob D. Augustynovich

Williams Honors College, Honors Research Projects

In an effort to increase efficiency and productivity, WARDJet was seeking a better actuation method for the cutting head on their waterjets. Current actuation methods were, for the most part, purely mechanical, relying on compressed air, springs, and water pressure to open and close the valve to 60,000 psi of water. Increasing the speed of the on/off cycle times of the waterjet would allow for faster movements of the cutting head from one cut to the next, increasing the overall amount of products cut in a day, week, and year. This obviously points to increased sales, increased profit, and increased …

Sparse Aperture Speckle Interferometry Telescope Active Optics Control System, Matthew Clause

Master's Theses

A conventional large aperture telescope required for binary star research is typically cost prohibitive. A prototype active optics system was created and fitted to a telescope frame using relatively low cost components. The active optics system was capable of tipping, tilting, and elevating the mirrors to align reflected star light. The low cost mirror position actuators have a resolution of 31 nm, repeatable to within 16 nm. This is accurate enough to perform speckle analysis for the visible light spectrum. The mirrors used in testing were not supported with a whiffletree and produced trefoil-like aberrations which made phasing two mirrors …

Effects Of Magnetic Field On The Shape Memory Behavior Of Single And Polycrystalline Magnetic Shape Memory Alloys, Ali S. Turabi

Theses and Dissertations--Mechanical Engineering

Magnetic Shape Memory Alloys (MSMAs) have the unique ability to change their shape within a magnetic field, or in the presence of stress and a change in temperature. MSMAs have been widely investigated in the past decade due to their ability to demonstrate large magnetic field induced strain and higher frequency response than conventional shape memory alloys (SMAs). NiMn-based alloys are the workhorse of metamagnetic shape memory alloys since they are able to exhibit magnetic field induced phase transformation. In these alloys, martensite and austenite phases have different magnetization behavior, such as the parent phase can be ferromagnetic and martensite …

Plant-Biomimetic Hydrogel Actuators: Creating Movement In Hydrogels Through The Study Of Plants, Christen Rhodes

Theses and Dissertations

Plants are sessile organisms that have developed methods of movement to respond to environmental stimuli. Some of the approaches feature the unequal expansion of cells and controlling deformation direction through fibers under swelling and drying. Hydrogels are three dimensional polymer networks that have the capacity for large volume changes due their affinity for water and can be tough and/or stimuli-responsive. In this paper, three preliminary plant-biomimetic hydrogel actuator designs are discussed and tested from wet to dry. The first actuator design, termed a 1%-0.1% bilayer, features two layers of different swelling and drying rates due to differences in cross-linking density. …

Advanced Design Optimization For Composite Structure: Stress Reduction, Weight Decrease And Manufacturing Cost Savings, Shayan Ahmadian

Master's Theses

An injection moldable chopped fiber composite actuator with detailed drawing and tolerances was designed within one year. A vendor was selected and a quote for injection molding tooling cost for production was obtained and the first prototype was built in addition of six months. The risks are identified and material characterization tests are proposed.

The objective of this project was redesigning an aluminum made actuator with a continuous fiber composite for weight saving purposes. After searching the literature and consulting with experts in the field it was concluded that manufacturing costs associated with continuous fiber composite are 3 times as …

Evaluation And Development Of Actuators For Lamina Emergent Mechanisms With Emphasis On Flat Solenoids, Justin Durant Black

Theses and Dissertations

Lamina emergent mechanisms (LEMs) can provide a way to meet the demand for more compact and inexpensive mechanisms. Previous research has developed LEM designs and identified applications for them, but many applications would benefit from suitable actuation techniques. This thesis presents the design considerations and a variety of applicable methods for internal and external LEM actuation in the macro scale. Integrated LEM actuator possibilities have been identified, each with its advantages and disadvantages depending on the application. Shape memory alloys are especially compatible with LEMs. Traditional actuators have also been discussed as a way of actuating a LEM from the …

Automated Adaptive Feeding Device, John Dolcini, Stephanie Smith, Pavel Yakovlev

Mechanical Engineering

No abstract provided.

Effect Of Piezoelectric Actuation On Curved Beams And Single Lap Joints, Calicia Johnson

LSU Master's Theses

Piezoelectric materials have seen a significant usage increase over the past decade. They have been found to be effective as either sensors or actuators in smart structure applications, which allows them to act more as an adaptive system rather than a passive system. Piezoelectric materials are very effective transducers which convert mechanical energy into electrical energy, known as the direct piezoelectric effect or they have the ability to convert electrical energy to mechanical energy, known as the converse piezoelectric effect. The absence of additional mechanical parts, its lightweight and high strength to weight ratio is what make piezoelectric materials so …

Aircraft Gearbox Dynamics Subject To Electromechanical Actuator Regenerative Energy Flow, Matthew S. Rutledge

Browse all Theses and Dissertations

To increase reliability and efficiency, standard aircraft components are being replaced with more electric subsystems aimed to reduce weight, conserve space, and improve energy management. One application of this process replaces standard hydraulic actuators used in flap or aileron movements with electromechanical actuators powered by an external generator. During different types of return movements, the electromechanical actuator will produce regenerative power that flows back through the generator and pulses into the engine-gearbox subsystem. The regenerative power, defined by characteristic amplitude, frequency, and other pulse attributes, coupled with the driving force produced by the engine may dramatically impact the performance and …

Design Of A Linear Ultrasonic Piezoelectric Motor, Scott L. Sharp

Theses and Dissertations

A new geometrically unique ultrasonic motor (USM) was designed using finite element modeling (FEM). A USM operates by vibrating a drive tip in an elliptical motion while it is in periodic contact with a driven surface. Piezoelectric elements are used to create the elliptical motions and are driven near a resonant frequency to create the needed displacements for the motor to operate. An idea for a motor frame was conceived that consisted of an arch, a center ground, and two piezoelectric elements connected to the center ground. End caps were added between the frame and the piezoelectric elements to reduce …

Micron-Level Actuator For Thermal-Fluid Control In Microchannels, Nurhak Erbas

Mechanical & Aerospace Engineering Theses & Dissertations

Effectiveness of an actuator is investigated for thermal-flow control in microchannels. First, simulations of a single actuator in a quiescent external medium are performed in order to study the parameters characterizing the synthetic jet flow from the actuator. For this purpose, a simplified, two-dimensional configuration is considered. The membrane motion is modeled in a realistic manner as a moving boundary in order to accurately compute the flow inside the actuator cavity. The geometric and actuation parameters of the actuator are investigated to define the effectiveness of the jet flow. The study is done initially at macro scales. Then, the flow …

Piezoceramic Actuator Placement For Acoustic Control Of Panels, Jeffrey S. Bevan

Mechanical & Aerospace Engineering Theses & Dissertations

Optimum placement of multiple traditional piezoceramic actuators is determined for active structural acoustic control of flat panels. The structural acoustic response is determined using acoustic radiation filters and structural surface vibration characteristics. Linear Quadratic Regulator (LQR) control is utilized to determine the optimum state feedback gain for active structural acoustic control. The optimum actuator location is determined by minimizing the structural acoustic radiated noise using a modified genetic algorithm. Experimental tests are conducted and compared to analytical results.

Anisotropic piezoceramic actuators exhibit enhanced performance when compared to traditional isotropic piezoceramic actuators. As a result of the inherent isotropy, these advanced …