Research Project - Separating Things

Good work today, folks!  First things first: there’s some homework we need done for next week.

Homework:

Amy/Olivia/Tara: Investigate separating silicon from silicon carbide based on particle size.  Amy, could you ask your dad for his expert opinion?  What are the sizes of the particles in silicon wire-saw slurry? Are there filtering techniques for separating particles of those sizes?  Is anybody already doing this?  Are there existing methods for silicon recovery from wire-saw slurry?  Maybe you could search Google, including patents.google.com and books.google.com.

Neshaya: Investigate separating silicon carbide from silicon based on density.  What are the densities of silicon and silicon carbide?  Is there a liquid with a density in between the densities of silicon and silicon carbide, that would allow one to float and the other to sink?  Is anybody already doing this?  Are there existing methods for silicon recovery from wire-saw slurry?  Maybe you could search Google, including patents.google.com and books.google.com.

Erika/Jadzia: Investigate separating silicon from silicon carbide based on magnetic properties.  Dr Linton suggested that because silicon is more conductive than silicon carbide, maybe you could separate it with a magnet.  Could you look up repelling conductors with a magnet?  Youtube and Google could be good places to look.

Nick: Investigate separating silicon from silicon carbide based on melting points. What are their melting temperatures?  If one melts at a lower temperature than the other maybe we could strain the solid out of the liquid like we do with coffee.  Or maybe the one that melts last would float or sink in the one that melts first, and the liquid could be poured out or drained.

Amy/Olivia: We need a timeline, pricing, and a decision on t-shirts. 

Tara/Amy: We need a Comet Warriors logo for the shirts.

As background to the homework, here’s a summary of what we did today:

We announced that Neshaya’s letter to the parent council got us $701.00!  Quite a letter and great job Neshaya!  The word for this week is “Neshaya”.

We reviewed the schedule and saw that we had only four weeks left before the tournament, including this week.  We’ve made good progress on the robot so far so we’re not too worried there.  We’re doing well on the core values and did another exercise on a) learning what those values are, and b) putting them to use in a card sorting exercise.  Remember: UPS!

We’re way behind on our research project so today we worked a lot on that.  The project is salvaging silicon sawdust, which is created when wafers are sliced from blocks of silicon.  Last week Olivia identified some things we might need for the project and we ordered them.  Based on Dr. Linton’s description, the problem is to separate silicon sawdust from the grit used to cut it, and the liquid it is mixed in.  The grit he said is used to cut it is “silicon carbide”, and the liquid it’s mixed in is “polyethylene glycol”.

Based on that description we ordered:
a) Silicon wafers
b) Powdered silicon
c) Silicon carbide dust
d)  Polyethylene glycol

Today we made a mixture of silicon, silicon carbide, and polyethylene glycol in a bottle to see what we had to work on.  It looked like a bottle of dirty water.

To get some ideas of how to separate things in general, we tried some experiments on a few more familiar mixtures. 

Separating Sawdust, Iron Filings and Sand

Sawdust, Sand, and Iron Filings

We started with a mixture of sawdust, iron filings, and sand and brainstormed ideas on how to separate them.  The ideas were:

Nick: Sift the mixture, or burn the sawdust.

Erika: Put the mixture in water to make the sawdust float.

Jadzia: Shake the mixture to make the iron and sand sink to the bottom.

Olivia: Use a magnet to pull out the iron filings.

We tried a combination of the different ideas.  We put the mixture in water, and the sand and iron sank to the bottom.  We then dragged a magnet along the bottom and pulled out the iron.  That left the sawdust floating, the sand at the bottom of the tank, and the iron stuck to the magnet.  Problem solved!

Separating Golf Balls, Ping Pong Balls and Mochi Ice Cream Balls

Mochi Ice Cream, Ping Pong, and Golf Balls

We then looked at a second problem: Separating a mixture of ping pong balls, golf balls, and mochi ice cream balls.  We brainstormed again and the ideas were:

Olivia: Heat them to make the ice cream melt

Nick: Give them to squirrels, who would eat the ice cream balls

Neshaya: Raffle them off and separate them by price

Olivia: Bounce them to see which bounce the highest

Nick: Separate them by color.

Olivia: Run them over grates with different size holes and the ping pong balls would fall through the smallest holes, the golf balls through the next larger holes, and the mocha ice cream through the biggest holes.

We again tried a combination of ideas: we ate the ice cream, and bounced the ping pong and golf balls.  The golf balls bounced highest, and if we bounced both types of ball on the floor the golf balls could bounce into a garbage can and the ping pong balls wouldn’t.

Our Research Project

Silicon, Silicon Carbide, and Polyethylene Glycol

We talked about how we came up with the different separation ideas. We had looked at the differences in the things we needed to separate: size, density, weight, melting point, color, magnetic properties, elasticity, color, smell.  We call these things "properties" or "attributes".

We decided to investigate the properties of silicon, silicon carbide, and polyethylene glycol and see what differences in properties we could use to separate them.  As described above in the Homework section, people volunteered to study certain properties and see if we might be able to solve our problem based on those properties, and to see if others had tried or were already using similar methods.

Let’s see what we can learn by next week and bring the information to our Tuesday meeting.  Thanks!

Homework Due on Tuesday

All right folks, we had a good meeting on Thursday to:

    a) pick a team name,
    b) create a team logo,
    c) decide how to raise money,
    d) pick a project.

We divided into two groups of five, and had each group come up with two possible names.  We then voted on the proposals and decided on "Comet Warriors" with 5 votes out of 10.  So item (a) is done.  Congratulations Comet Warriors!

That left items b, c, and d.

For (b) we decided to let anyone who wanted to create a logo, and we would vote to pick our favorite design tomorrow (Tuesday).  If you have a proposal for a logo, please bring it with you tomorrow.

For (c) we came up with two plans for raising money.  Amy and Georgia are going to organize a Haunted House for the school's Family Dance night.  For tomorrow they're going to develop a plan describing where the haunted house will be located, what the hours of operation will be, who will staff it during the dance, how it will be laid out, what items they need.  Thank you Amy and Georgia!

The second fundraising plan is to ask the Parent Council for money.  Our Communications Manager, Nashaya, volunteered to write a letter to the Parent Council on behalf of the team, listing our expenses for the season and asking them if they could contribute.  Thank you Nashaya!

For (d) we identified four contenders for e-waste research projects: i) heavy metals, ii) silicon dust, iii) cell phones, and iv) computers.  We asked those most interested in each project to prepare a presentation for Tuesday describing the current state of handling that type of e-waste, and what innovation(s) they thought we might try as an approach to reducing, recycling, or re-purposing it.

The volunteers were:

Jadzia - Heavy metals
Olivia - Silicon sawdust
Lyla - Cell phones
Nick - Computers

We look forward to your presentations tomorrow!

And the secret work for this week is Gnoljan (a Swedish word pronounced nol-yan, and meaning "comet").  Actually that's not true.  It's a word I made up using the initials of the people who volunteered to have something done by tomorrow.  See you then!

Interviews with Experts

Yesterday we spoke with an expert on the electronics industry about e-waste.  Olivia emailed Dr. John Linton, VP of Direct Wafer Process Research and Development at 1366 Technologies to see if he could talk to us about e-waste. He called us at lunch to see how he could help.

The electronics production process, as he described it, consists of first producing silicon wafers.  These are made by making very large blocks of silicon metal, which are very expensive to make, and then sawing them up into thin slices.  The process of sawing up the silicon into wafers wastes almost half of the silicon as sawdust which gets thrown away.

Once the wafers are made they are treated with special metals including indium, which give the silicon the special properties it needs to work in phones, computers, and other electronics.  Another metal used a lot in electronics is cadmium, which is used in batteries.  The problem with these metals is that, although they allow us to make amazing electronics, when those electronics end up in landfills the metal can leak out and pollute rivers and streams, groundwater, and other parts of the environment.  The metals, even in small amounts, can be very bad for your health.  There are laws regulating the use of cadmium in electronics, but there are none for indium which is just as dangerous.

When we asked if he thought there were problems we could work on in e-waste he suggested three:

1) Find a way to save and re-use the silicon sawdust that represents half of all the silicon produced.
2) Apply some science to the classification of metals used in electronics to see which metals should be more carefully controlled and which shouldn't.
3) Find a way to get used electronics into the hand of people who could use them instead of putting them in landfills.

The interview and his email are below (and the secret word for this week is Maren):

Interview with Dr. John Linton, VP of Wafer Process R&D, 1366 Technologies

10/13/2015

Dr. John Linton:  Hello.  Is Olivia there?

Olivia: This is Olivia.  I’m sitting here with the Comets Robotics team.  Thanks for calling.  We wanted to talk to you today about e-waste and had some questions that we hoped you could answer.

Dr. John Linton:  All right.  I’ll do my best.

Nick: What do you do?

Dr. John Linton:  I work for a company that produces silicon wafers for solar panels.  Right now the silicon wafer is the most expensive part of the panel.  I’m working on a new way of making these solar wafers that will allow them to be half the cost of normal solar wafers.

Olivia: OK, so are there any waste problems with that?

Dr. John Linton:  Well, one of the waste problems that we’re tackling is that when you make a solar wafer the first thing you do is make an enormous block of silicon.  It’s about 1 meter on a side.  And then you take what is called a wire saw to saw it into smaller blocks.  And then you take that wire saw and saw the blocks into smaller wafers.  And every time you cut this block to make it smaller you generate sawdust of silicon, and you have to throw all of that sawdust away, which is waste.  So the method I’m working on requires no saws and no sawdust.  And so that’s one of the ways that we’re tackling the waste problem.

Olivia: OK.  Are there any other opportunities in the e-waste department?

Dr. John Linton:  There are lots of opportunities if you thought about different ways that heavy metal wastes are generated in the electronics industry, and thought of ways to effectively separate and recycle those heavy metals.

Olivia: OK

Dr. John Linton:  Those heavy metals could be in batteries, they could be in electronics like computers and smartphones.  Even things as simple as a capacitor in a smartphone can have a heavy metal called Tantalum in it.

Helen: Hi John, this is Helen.

Dr. John Linton:  Hi, Helen.

Helen: So I have a question.  After you’ve separated these heavy metals then what would happen to them?

Dr. John Linton:  Well, right now heavy metals aren’t often recycled.  They’re left in landfills and they can contaminate the soil, and then the drinking water.

Nick: How is it handled?

Dr. John Linton:  Well, you have to handle heavy metals like cadmium, for example, very carefully from the time that it’s mined all the way through manufacturing of a part, and then disposal of the part.  When you make a part with cadmium you have to show that it’s encapsulated such that if it gets in contact with the soil it doesn’t contaminate the soil.

Olivia: Why isn’t it being done already?

Dr. John Linton:  Well, because heavy metals make very good products.  People really enjoy their cell phones and their TVs and batteries, so it’s very difficult to get laws to prevent these products from being made.  Now there are places where laws have been made requiring that things be recycled safely.  Car batteries, for example, contain lead, which is a heavy metal, in standard car batteries, and there is a system in place for safely recycling them.

Olivia: OK

Nick: How could it be handled better?

Dr. John Linton:  OK, well there are laws in place.  How could it be handled better?  Actually, I think some of these laws don’t depend enough on science.  So I wish there was more science done to show that some heavy metals are safer than others, and others are very dangerous.  I wish there was more science done to show which ones are the most important.

Olivia: What’s an example of one of the laws that are in place already?

Dr. John Linton:  Ah!  Well, let’s see.  There is a heavy metal called cadmium, which is dangerous.  There’s another heavy metal called indium, which is also dangerous.  But while cadmium is controlled, indium is not.  So I wish there was a lot more science on all the heavy metals.

Helen: Now, are the problems with some of those metals caused by these guys having strong lobby groups?  Or is it just that they don’t feel that it’s important enough.

Dr. John Linton:  Sometimes it’s just the lack of science.  So there’s this group of heavy metals are covered by a law called ROHS (Restrictions on Hazardous Substances).  It’s a European rule that covers six or eight heavy metals, and just kind of ignores the rest because it doesn’t have data.

Dr. John Linton:  What are you guys going to do with all of this information?  Do you have to do some kind of a report?

Olivia: We have to clearly distinguish a piece of trash and find a way to keep it out of landfills.

Helen: They have to identify a problem and come up with an innovative solution, or an improvement on something that’s already being done.

Dr. John Linton:  Well if you look a cell phones or something like that, there are so many cell phones sold, and there are a lot of people who need cell phones.  Maybe there’s a way to generate, or to get these old cell phones to people who need them without throwing them away. I know I’ve got a drawer full of three or four old cell phones that I don’t use any more.

Olivia: Does the silicon end up in landfills?

Dr. John Linton:  Well, silicon is actually a very green material.  The earth is made up of 60% silicon dioxide, also known as sand, or glass, or other things like that.  Silicon is everywhere and makes up part of our bodies and almost everything you stand on.  It’s actually a pretty safe material.  That’s one of the reasons I really like solar energy and like working in solar energy.  Because we’re using a very green material to make electricity.

So you asked me about recycling silicon and I started talking about heavy metals which is a topic near and dear to my heart but is one that the solar industry doesn’t really have a problem with.

Georgia: Do you have any ideas of what we could do for a project?

Dr. John Linton:  Well, I mentioned in an email to Olivia’s dad that learning how to recycle the silicon dust, the silicon sawdust from the solar wafer making industry, was one good idea.  While we were talking on the phone I thought of another idea, which would be to find a way to separate working electronics, such as cell phones or old TVs and so on, so that people could still use them.  If they’re putting them in landfills maybe you could find a way to use the phone or the TV.   Take them apart so that the parts could be recycled.  What if there was a way to take an old TV and find a way to take the glass out and turn it into a window or something?

Helen: Nick has something he wants to say.

Nick: Thank you!  Thank you for taking the time with us.

Dr. John Linton:  Well you’re welcome!  If you’ve got any more questions Olivia’s got my email address.  You can email me any other questions and I’ll answer them if I can

.

All: THANK YOU!

Helen: I have a question.  How’s Maren?

Dr. John Linton:  Maren is doing great!  She’s really enjoying kindergarten. 

Helen:  Glad to hear it.  Well thanks so much for talking with us.

All: Thanks!

Dr. John Linton:  OK you guys.  Good luck and let me know if you have any other questions.

Email from Dr. Linton on project ideas:

Regarding research topics, here is an area that occurred to me right away, because it is a problem for our competitors. A lot of energy goes into making silicon, a very interesting process from sand to Si. Solar manufacturers then melt it, and crystallize it very slowly (2 weeks) so that as it solidifies, it excludes any impurities. That is a lot more time and energy. Then they saw it up to make 6"x6" wafers, losing about half of it to "sawdust". The saws they use are wire saws, and they use some kind of grit to make them work. because this grit ends up mixed with the nice pure silicon, they throw it all away. in other words, half of the energy they used to make it is wasted.

Our process makes wafers one at a time, by putting a cold mold into a hot silicon bath. No waste.

But it would be interesting to explore the standard process, showing how Si is made from the sand, and how much energy is wasted by throwing the sawdust away. And maybe they could do some settling experiments or something to see how easy/hard it is to separate. If you could separate it, you could put it back into the process. But it must be hard, because they don't. 

Let me know if that sounds interesting, i may have some background material that could help Olivia and her team.

E-Waste Background

For next week please do some research on e-waste.  There are good resources available on the FLL Trash Trek website and you can also check out this video at  PBS.org

Game Changing Solutions

On Friday we discussed trash and solutions.  We looked first at the idea of throwing trash away, and learned that "there is no away".  Stuff we get rid of just ends up surrounding us, as we could see in pictures of trash picked up in just a 1-hour walk around town.



We then talked about solutions: incremental vs game changing.  A game changing solution is one that isn't a small improvement to the strategy of the current game, it's one that changes the rules to allow completely new strategies.

The example in the video below was how to deal with plastic bags.  The incremental solution was to give people gift cards if they brought the plastic bags in for recycling, resulting in fewer bags ending up as litter, in landfills, etc.

The game-changing solution was to organize people to get plastic bags outlawed, so they would use canvas bags instead, resulting in zero plastic bags in landfills or as litter.

The video also made the point the maybe we should design around "better" rather than "more".

On Tuesday we're going to talk to a manufacturing expert about e-waste.  Olivia emailed him and he can talk to us at 11:30 for half an hour.  He lives in Boston and will call us at lunch.

His name is Dr. John Linton.  The secret word this week is, you guessed it, "John".  Dr. Linton has worked for 25 years designing and manufacturing things related to cement, camera film, drug testers, and electronic equipment including printer cartridges, TV displays, and solar cells.  He knows a lot about electronics, what goes into making them, how they're used, and where they end up when people are done with them.