NITINOL GENERATOR WITH 0.01-1 WH/DAY ON DEMAND OUTPUT

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: SMALL BUSINESS GRANT
• Reporting Frequency: Annual
• Accession No.: 1006337
• Grant No.: 2015-33610-23554
• Cumulative Award Amt.: $99,981.00
• Proposal No.: 2015-00745
• Project Start Date: Jun 15, 2015
• Project End Date: Feb 14, 2016
• Grant Year: 2015
• Program Code: [8.12]- Small and Mid-Size Farms

Recipient Organization
KELLOGG'S RESEARCH LABS LLC
89 MAIN ST. BASEMENT UNIT
PLYMOUTH,NH 03264

Performing Department
(N/A)

Non Technical Summary
This project is a subset of a larger project which has the goal of generating electricity from changes in atmospheric temperature through space and time. The near term goal is to provide a higly durable power source for agricultural sensors so that farmers will not have to change batteries or rely on brittle photovoltaic cells. Longer term applications include scaling the tecnology to power remote and limited use buildings, active road signage, and arctic and antarctic installations.The purpose of this project is to remove the greatest source of inefficiency in our proof of concept model--the attachment of nitinol wires into the framework of the generator. Previously, the wires had been clamped in place. However, the clamping was not very consistent, resulting in varying tension in the wires and a loss of the bulk of the work generated. By using the ring terminals, the wires will be able to be accurately cut and consistently attached to the generator so that each wire has the same amount of tension and the work output is maximized.We will be using tensile testing to determine the ultimate tensile strength of the attachments as well as optical microscopy to help evaluate the failure mechanism. Samples with good performance will be prepared again and tested for fatigue resistance, determining the true value to the cyclic nature of the generator.With the completion of this study, we can begin optimizing the generator to fit the various needs, as stated above. With the agricultural sensor application, the main benefit will be an overall cost redution in the use of crop monitoring sensors, which has the extended benefit of reducing the environmental impact of agriculture.

Animal Health Component

50%

Research Effort Categories

Basic

50%

Applied

50%

Developmental

0%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
402	7210	2020	100%

Knowledge Area
402 - Engineering Systems and Equipment;

Subject Of Investigation
7210 - Remote sensing equipment and technology;

Field Of Science
2020 - Engineering;

Keywords

diurnal cycle

energy efficiency

nitinol

power generation

renewable energy

sma

Goals / Objectives
The primary goal of the project is to determine the most cost effective method for attaching a titnaium ring terminal to a nitinol wire. Ultimate tensile strength as well as fatigue resistance are both considered valuable data for this project. We will examine:1. TIG welding2. Mechanical crimping3. Nd:YAG laser welding

Project Methods
As previously stated, we will be examining the attachment mechansim between a nitinol wire and titanium ring terminal. Data collection will be conducted with a tension tester. Samples with a high ultimate tensile strength will be prepared again and tested for fatigue resistance (cycles to failure). In order to directly observe failure mechanisms, optical microscopy will be used. This will assist in detecting bad data from poor sample preparation as well as directing future development work.

Progress 06/15/15 to 02/14/16

Outputs
Target Audience:This project consisted of only laboratory work. Target audiences reached by the work included internships in the lab in addition to educational talks given to local high school students. Changes/Problems:1. Significantly more time was spent on surface preparation and the evaluation of surface preparation techniques than was originally expected. 2. Altering the parameters of the Nd:YAG laser turned out to be much more complicated than was originally expected, based on the literature reviews. More than four months were spent studying the Nd:YAG laser waveform and additional time needs to be spent studying this attachment method after a scanning electron microscope has been acquired. 3. The company spent some of its own money to conduct a preliminary scanning electron microscopy study to try to determine why welds were breaking at forces lower than expected. This study uncovered at least six microstructures that had never been observed by anyone on the team. The SEM scans have been reviewed by four other materials scientists (each having experience with nitinol), none are familiar with these structures. Significant study is required here. What opportunities for training and professional development has the project provided?1. This has provided two internships to undergraduate students. 2. This has provided professional development for one associate at the company. 3. This has provided professional development for two scientists at the company. How have the results been disseminated to communities of interest?1. An abstract has been submitted to the ASME Power & Energy Conference. 2. A presentation was given to members of the New England Clean Energy Council. 3. A presentation was given to members of the CleanTech Open. 4. A presentation was given to undergraduate students at Houghton College. 5. Our interns wrote papers about their work with the company which were published within the academic circles What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? 1. TIG welding: a. A successful set of welding parameters was developed allowing for a strong attachment of NiTi to titanium ring terminals. b. It was determined that grade 5 titanium was a much better fit for the ring terminal than grade 2 titanium, due to the higher tensile strength, allowing for a stronger terminal with the same physical geometry. c. Surface preparation methods were developed which optimized the strength of the weld. Electrochemical polishing yielded the strongest bonds but mechanical polishing was effective enough for this application and is much simpler and cheaper to implement on a commercial scale. 2. Mechanical crimping a. It was found that mechanical crimping was not a good fit for this application. 3. Nd:YAG laser welding a. a. A successful set of welding parameters was developed allowing for a strong attachment of NiTi to titanium ring terminals. A good waveform was generated with the possibility for continued improvement in weld strength. However, this will require scanning electron microscopy for further examination. b. It was determined that grade 5 titanium was a much better fit for the ring terminal than grade 2 titanium, due to the higher tensile strength, allowing for a stronger terminal with the same physical geometry. c. Surface preparation methods were developed which optimized the strength of the weld. Electrochemical polishing yielded the strongest bonds but mechanical polishing was effective enough for this application and is much simpler and cheaper to implement on a commercial scale. d. The repeatability of the laser welds was very high, even under manual control of the laser. Spending the money to automate the laser should yield even stronger welds with an even greater level of repeatability.

Publications

• Type: Conference Papers and Presentations Status: Under Review Year Published: 2016 Citation: Modular Power Generator, ASME Power & Energy Conference