Video Transcript – Self Sealing Nitinol Lid

[Music]

Well it is 3:30 so I think we will go ahead and get started. Thank you all for coming. We’re team smart and this is our senior design showcase. So some quick introductions my name is Carolyn Murrey. I’m a senior in mechanical engineering. I’m currently the president of phi sigma rho sorority and the co-team lead for Boise State’s microgravity team. After graduation I’m hoping to work in aerospace.

Hey I’m John Howard. I currently am a mechanical engineer senior and I currently work at a company called Kytek Automation. I do a lot of R&D for them and I’m really interested in robotics as well as systems engineering.

My name is Dylan Rolleigh. I’m graduating with a degree in mechanical engineering and a minor in applied math and started my undergraduate work doing some product development stuff with the new product development lab actually. And so product design is one of the things that I’m interested in but kind of the end my undergraduate work I got into robotics and automation and I’m currently working for a company called Bastion Solutions which is an R&D branch of Toyota and hopefully we’ll receive an offer from them maybe sometime next year.

I’m Caleb Picklesimer. I’m also a mechanical engineering senior set to graduate here in a couple weeks and I’ll be pursuing a job hopefully in aerospace or automation. I really like cad modeling and the R&D work so I’m hoping to get a job that utilizes those two things.

The client for our project is Dr. Deng. He works here at Boise State running a research lab. So to start, a little bit about our project, our client came to us with a very unique project. He’s currently studying the capabilities of nitinol and other smart materials in his lab. He is looking for a way to draw more attention to his research and ultimately hopefully more funding as well. So he approached our team asking for a design and prototype that can demonstrate the shape memory capabilities of nitinol wire. The prototype that was designed and built was almost entirely up to the discretion of our team so long as it was eye-catching enough to entice viewers to ask our client about how it worked.

So a little bit about what nitinol is. When our client came to us asking for a demonstration that utilizes nitinol our first step was learning more about what nitinol is since we weren’t overly familiar with the material or its properties. Nitinol is a nickel titanium alloy whose properties were discovered at the naval ordnance laboratory which is where it got its name. The right combination of nickel and titanium create an alloy that has both super elastic and shape memory properties. But our project is primarily focused on the shape memory.

There are two key components of nitinol’s shape memory capabilities that affected our project. First is the train shape and second is the transition temperature. So nitinol can be deformed or bent into many different shapes when it’s below its transition temperature but when the wire is placed in an environment that is at or above its transition temperature it returns to its train shape. Our project specifically focused on nitinol whose trained shape was straight and whose transition temperature is around 102 degrees Fahrenheit.

So kind of moving on from that you know our scope of this project was really difficult because normally on senior design projects you have a very specific goal and really specific specifications. So the work envelope is pretty small on you know the creativity inside of it there’s a lot of engineering that goes into it and not as much invention. This project was pretty much all on the invention aspect.

So there’s a lot of brainstorming, a lot of trying to figure out you know what defines cool, we can come up with an eye grabbing. So the first thing we did was just look what look what’s already out there you know. Currently NASA has a cool space suit that the nitinol is inside the spacesuit. So it seals to the body temperature of whoever’s inside of the spacesuit. Similarly this benchmarking that we did here was of a nitinol motor. It’s a nitinol string that’s trained to be straight and then as you put the bottom pulley inside the water it makes it tension hopefully, and that creates [inaudible]. Next slide please.

So with what’s already out there that kind of gave us a starting point to do some brainstorming but we also had some pretty specific or pretty general needs from the client. One of them was obviously it had to be safe for the operator. You know we were using boiling water and we were using or you know some kind of hot activation for it. So obviously where there’s heat there’s going to be possibility for burns or something like that so safety was a big priority for us.

It needed to be a unique design. You know, something that catches somebody’s eye. Carolyn already touched on this and it is a very difficult thing to grab but that was kind of the general goal we had to we had to go for. So we came up with a lot of ideas to do that.

Lastly we we needed it to be just a really easy portable really easy to assemble and take somewhere. So we wanted him to be able to either have somebody up at his lab and for him to be able to show people. We also needed to hopefully get through TSA security. So having something in a carry-on bag was something we were looking for as well. Next slide please.

So we came up with about 20 ideas for Dr. Deng. First we narrowed it down to about five forms so that he could kind of kind of go through and see what his favorite ones you know or which one was his favorite. Because we had so many ideas that you know some of them were really good, some of them were not so good. So we kind of gave him our top five ideas and he chose the self-sealing coffee lid. One of the reasons why was because it’s pretty applicable for what people need right now. Having a mechanical or mechanically activated seal is really desirable in case there’s any power issues or power outages at like say a nuclear plant. It’s also advantageous for something like a kitchenware or something like that as well. So with that I’ll turn it over to Dylan.

Thanks Johnny. Yeah, so I think maybe that devious finger trap needs a little explanation. I was really upset that we didn’t do that one. So you know, nitinol changes shape with temperature so we had thought that we could perhaps weave it together in a way so that when you put your fingers into that shape much like what you see in that picture there above devious finger trap like in cold water that you could easily put them in there. You pull it out of the cold water and it would cinch down on your fingers. And then there would be no way of getting it off unless you put it back in the cold water so it would phase change again and then push it together. So you know have people at a conference walking around with a finger trap they can’t get off their hands. So Dr. Deng didn’t approve and we moved on anyway.

So self-sealing coffee lid. First we needed to become familiar with the material. We ordered a wide range of samples. Different phase changing temperatures and different gauges. And we tried to you know discern the forces that we could get from each of those wires and how accurate the phase changes were to the temperature that they the spec. And craft you know testing apparatus much which you see there in the picture where we have a spring that’s being stretched because we have a wire that wants to go back to a straight position and we’re putting the bend part into the hot liquid. We measure that displacement with a caliper and we had already calculated the spring constant beforehand for this specific spring so we could then solve for our force on the spring. And we kind of used this as a tool. It wasn’t, you can see that you know we have some zip ties that we’re using. We’re literally using toothpicks here. And so there’s a lot of error that was occurring but we could kind of rank our wires which ones were the strongest, which ones were the weakest, and so forth. So we used that [inaudible]. We just knew that we wanted to start with the strongest one and then if we needed to pick one that was kind of weaker we could you know maybe choose one that was half the strength.

What we really wanted to do was use Dr. Deng’s precise measuring instruments. He had four stages in his lab. He had all kinds of already well thought out experiments. But you know because of covid and just the logistics of two of our members getting covid, it really didn’t work out. So we had to just hope that the strongest wire was what we needed to move forward. But you know, we attempted to use and it was kind of good for us to get our hands on the wire and see what would happen whenever it phase changed so – qualitative experimentation. Next slide please.

So the design part process always starts with brainstorming and a little bit of paper on pencil. This is a collage of our concepts that we came up throughout the process. We really built on different concepts so that first drawing that you see rotating lit idea was really complicated we kind of moved away from that that we didn’t even attempt to prototype it. That first folded wire idea was our prototype one. The linkage idea is our prototype two. And our gun trigger idea is prototype three. And we we did make all three of those and test them. And we made that first one, learned some stuff from the testing, and then moved on to the linkage idea. And I’ll talk at the next slide about like what we learned between these ideas but I just wanted to kind of show you, you know this is real with all of us around the table shooting ideas back and forth and we kind of end up with something like this and then we move on to the next phase. Next slide.

All right so what happened with that prototype one. We liked it. It was low profile. We noticed when we 3d printed it and kind of assembled it that the lid didn’t open as you know much as we wanted it to. It’s about 30 degrees so we were a little concerned about the wow factor being fulfilled, that part of the requirement. We also have them situated in that prototype one picture. The wires were able to rotate so when they would heat up and phase change they would you know, go back to their trained position however possible. And and a lot of times that was in undesirable ways. So the other really important thing that we learned was that the steam wasn’t hot enough to create the phase change and as quickly and as short of time as we wanted it to. So it would happen but we had to like leave it on top of the coffee lid for a while and you come back and it’s kind of closed maybe all the way. So not what we were looking for.

So we decided we needed to put the wire in the liquid. It needed to be submerged. We needed to have a way to fix that wire to our lid. And we needed our our lid, our spout latch, to have a little bit more drastic opening range. So that’s what you see us trying to achieve in prototype 2.

This is our linkage design. The turquoise wire is actually being held in that slot with a set screw and it’s closing that lid. The lid almost opens 90 degrees and then it has a pin that slides in that open slot there. So that allows us to create some mechanical movements, some kinematics, so that the wire is actually in submerged in the liquid. But that also had some problems having these linkages proved to be kind of difficult. The wire needed to be actually fixed to one of the links and so that required us to do some soldering which was a whole another task in and of itself. And you know, we thought we might want to go back to the drawing board and Caleb let’s talk to you about you [inaudible]. We’re reporting back to him at each this phase of this design process and he had some really good insight so I’ll let Caleb speak to that.

So for prototype 3 taking into account Dylan’s talking about the lid. They closed a little slowly and he wants something that’ll wow people. So he kind of nudges in the direction that instead of using the nitinol wire to actually power the opening and closing of the lid we would use the nitinol wire to trigger a spring [inaudible] two different types of wires.

Wire number one documented here. It’s larger, has more force than wire two. It also has a higher transition temperature of over oh somewhere around 140 to 160. So anything above that it’ll want to straighten out.

Wire number two has a transition temperature of right around 100 or a little under and so pretty much all the time wire number two wants to straighten out.

How it works is before there’s hot water you can see in the leftmost picture it’s in the open position. As the water fills up, the water heats up wire number one to above its transition temperature. And if you look in the right most picture you can see that the wire number two or wire number one the thicker wire, is straightening out and moving the green trigger out from under the blue catch face of the stopper. The stopper is pulled back as you can see in the middle picture there by the spring and it pulls the latch shut. And so as long as the water is above 140 degrees ish you can’t pull the latch back up and it stay. So it always wants to flop back over. Once the water cools down below the transition temperature of the bigger wire, the bigger wire goes back to being ductile and the wire number one which is always active pushes the trigger back into the left-hand picture orientation. And when you pop the lid and then you know everything is good to go. And you can access it. And it uses two different types of nitinol which was you know pretty cool. So we feel like this design is a pretty good solid basis. But how might we improve on this design? Caroline, next slide please.

Oh that’s right. Here’s a video of the design working. See the water is filling up.

We should have inserted a sound of a crowd going wild right there.

Yes. Next slide please.

So what’s next? You can tell in the video that the lid is just a portion of the lid for testing the actual mechanism. The final [inaudible] having the entire lid and then having a seal where nitinol wire is embedded in the seal all the way around the cup. And when the hot water activates the seal it wedges the lid inside the cup and so the lid won’t come out of the cup. The water won’t come out of the lid. And you have pretty much a sealed container until the water cools back down and the nitinol will release both the stopper and the lid. Next slide please Caroline.

So thank you. We’re going to open up if you guys have any answering for you or just talk about it in general.

Somebody asked if they could watch the video again.

I have a very important question.

Sure.

The settlers game that was in the last slide.

Oh good eye. I wondered who’s this asking that question? It doesn’t show me.

That’s your older brother Michael. Congratulations! This looked great. And to all of you. You all did a great job.

I should have guessed that it was you who was asking that.

I don’t think we actually finished that game. We got sidetracked with actually working on the project. But we were supposed to do a team building exercise so we you know started to play a game where we all played against each other and are supposed to conquer each other. So that was our team building exercise.

Yeah that was the best answer possible for during your work presentation. We were distracted by work and unable to complete the game. That was perfect.

Runs in the family.

Dylan this is Calvin Allen I have a question for you.

Hey I’m sorry I missed the very beginning. So I’m really hoping this isn’t a question you already covered. So the customer in this case was the the professor. Did this check all the boxes for him? Does he feel that this is an adequate exhibition of what the material can do? Was he pleased at the end?

Yes. We are meeting with we met with him a week ago or perhaps the week before that to just kind of show him where we’re at, which is kind of what you’re seeing here. He is happy. He is very happy with the the quickness of which the the latch shut. He is I think hoping, we still need to deliver on the full lid so we have that proven middle section, the mechanism part. But we still need to print any durable material the seal that’s going to mate with the from the lid to the actual the rim of the cup. Dr. Deng might be in the meeting. I’m trying to click through here.

He’s not. He’s not.

Okay. I was hoping you could hear straight from him. [inaudible]

Your next steps were durability and that co is. I was curious if that tied directly to what the customer wanted or that was just felt what was right as a next step for you guys. But that makes sense. Yeah sorry go ahead.

We didn’t get to show you that during our testing it was kind of tricky because we had to do several prints. That material is FDM. So it was warping and melting in the hot water. So we’d get like two tests out of them and then things would start to go wrong. So we’ll probably print that last iteration, that last prototype, in a SLA durable lab

Does the process by which you set the the austenitic transition temperature. Is that repeatable enough that you could actually come up with a true product out of this? I mean if somebody pushed you to say, yeah we want this to close at 148 degrees or something, how close could you get to that in that lab?

Caleb you looked at it and said that there was some air that occurred at the phase change temperature. So Caleb you might want to speak on this a little bit.

Yeah so the phase change the wire. The temperatures, there’s a hysteresis effect where the wire like once it is, so once it reaches this transition temperature and it goes through the austenitic demarcanistic phase change and it comes back there’s some hysteresis. So they give you a plus or minus, I think it’s plus or minus 10 degrees Celsius of where it might phase change at. And from what I understand it is a very very very tiny margin for producing predictable wire. So like it’s roughly 51% to 49% nickel to titanium by molecular weight not by volume. But like 51.01 percent might be a different phase change transition and nickel and titanium were both hard to process just from the research that we did in the background. So they’re actual science that’s going on behind it. But from a mechanical standpoint obviously it’s fairly simple. But I mean we’re in these.

Yeah now that’s fair. Yeah.

The reason I ask is we we use nitinol quite a bit at Medtronic when I worked there for self-expanding stents and we faced the same thing. That you could do your best to control the process but really starting with the ingot material you might not ever get there. So I was mostly curious if you knew enough about the background to understand what you’re up against which it sounds like you do.

Yeah it’s basically one of those things that if you need a hundred and 140 will work and then just shoot for higher than that by the margin of safety.

Great, thanks.

Good question.

So this may be a detail but how do you drink the coffee if you can’t get the lid open? If the lid is slammed shut and you can’t get the can’t get the lid off?

That’s actually the point.

Yeah that’s the point.

Okay.

Yeah, yeah.

Call this the McDonald’s lid. It won’t let you drink the coffee until it’s cooled down enough.

Whenever it cools, Doug, so ours was at about 105 degrees fahrenheit. So plenty cool enough to drink. When you finally you can open the lid and anything hotter than that or like, Calvin pointed out, you know like 115 or more. If you open the lid, you can open it because you can do so with the strength of your finger and then if you let go that trigger is engaged in the direction where the spring will just snap the lid shut. So it’s telling you the coffee’s too hot to drink. You’ll burn yourself. Don’t drink it.

Something that occurred to me, well like it’s probably I don’t know it’s an interesting thought though is once it cools down there’s no way to close the lid because the nitinol is then controlling the lid being in the open position so you’d physically have to remove the lid trip the trigger every time you wanted to close the lid like if it were a carrier cup. That occurred to me today.

Details.

You get tunnel vision. You get wrapped up.

Yeah, I think we did talk about that Caleb.

So this is a stab from the past. But when I was a senior, one of the senior design projects was called the ISO thermal cup. And this was a two layer cup filled with a two phase material that at room temperature the material was solid. You pour in and the two-phase material would cool off the coffee from a hot temperature down to a a drinking temperature down to about 140 degrees and it would keep it there for 20 minutes with the lid open.

That’s super cool. So you control… how did you control the temperature at which it cooled down to I guess the amount of the the liquid that’s in the double layer wall?

Yeah, yeah. You control it that way. It actually, one of the materials was beeswax that would melt at about 140 degrees and you know that’s what it would do. It turned to a liquid at about 140 and it would stay that way until enough heat dissipated out of the top, you know, convection out of the top and then it would change the material to a solid again. And then it would suck the temperature down real fast while it was cooling. But you had 20 minutes to drink your coffee at a reasonable temperature so anyway nobody else was asking questions so I thought about that while you were talking. That invention like this invention, I don’t think the ISO thermal cup ever got past the drawing board or past the prototype board.

Sounds like you guys did a fun job. That’s great. Is there a group that’s going to continue this next semester and try to perfect it?

I think that’s a good idea I know Dr Dang is interested in getting a patent on this. He had mentioned that in our last conversation so for our senior design project and he
could move it further a little bit.

That’s great. The PHD gets the patent and you guys get squat. Okay, well that’s all right.

I get a degree. I’m pretty happy with that.

That’s right.

[Laughter]

We’ll be ecstatic in like a week and a half.

You guys are doing great.

Yeah this is pretty impressive. I have a question that’s a little bit off of probably most of y’all’s target area of science. The material science is awesome. And the project was really good the design was very impressive. But I noticed on Carolyn on your introduction in the team thing that you had also put product management as a list. Did y’all actually do any, follow any methodology in your interaction with Dr. Deng in determining what the client requirements were and how you were meeting them and altering any changes you know based on what you were finding in your prototypes? And if so how did that go?

We were updating him during our prototyping. It went pretty well. He gave us a lot of really good insight. Especially between the second and the third prototypes. The trigger mechanism that we ended up using in the third prototype was his idea. He was talking about using a mouse trap type of triggering mechanism to get it to be a little bit of of a quicker snap. So it went really well updating him as we went along throughout the last two semesters.

Well I thought you had a pretty quick snap on the first prototype isn’t that the one that bounced up and spilled water?

So I think that was the second one. Our first one was really slow.

Well I noticed there was one and I thought it was the first one that it actually came off?

Yeah.

Am I remembering that correctly that one of your prototypes?

Yeah that was in the video on our website and that was that linkage prototype. And I can tell you doing that and I didn’t really think about the diameter of the coffee cup narrowing. So I made the… I designed it for the opening in that footprint so whenever it actuated it expanded out to the the size of the top and so I didn’t have anywhere to go but up when it hit the walls of the coffee cup down low and so yeah it popped out of there and I nearly threw boiling hot water and Caleb.

A very good project. Very impressive stuff.

Johnny did a really good job of managing the spreadsheet that we had. We had different milestones and I mean that was a lot of project management work. That was shared with Dr. Deng and so he could see you know at any time he could pop in there and see at what point we were at. You know we had each step broken down into subtasks and a timeline of basically a Gantt chart and then checks were being you know filled across that as we went along over the course of two semesters.

We are at four o’clock. I mean I could stay on here and chat with all of you for a long time. I might have to set up times outside of this. But isn’t there another… shouldn’t I guess we should break to let people who want to see the… isn’t there a part two where other teams are going?

Yeah there’s part two. Yep.

I guess we can join too. So unless there’s any last questions we’ll give you guys a few seconds here, you got something. No last burning desires.

That’s really burning comments.

Yeah okay cool. Well thank you guys for attending. I really appreciated your support and we were you know pleased to present our you know work that is a culmination of two semesters and leading up to us receiving our our undergraduate degree. So if you guys have any follow-up questions you can also email us and you know hopefully we’ll see some of you around campus in the future and otherwise, yeah, thanks thanks everybody for attending.