Tag Archives: Science

Droplet microfluidics with acrylic part 6

I’m just going to do a brief update today on the microfluidics project. We set out to make acrylic plastic microfluidic chips that could generate tiny droplets of water in oil. Eventually, I hope to use these droplets to make polymer particles. We can make polymer particles from a water in oil emulsion. We usually just shake the mixture vigorously to make the emulsion. But that makes all kinds of different sizes and causes other problems as well. So now we’re going to use a much more complicated method: microfluidics.

I have some experience with droplet based microfluidics. I worked on it in graduate school. It’s a simple idea. Flow oil and water through tiny tubes that merge into a single tube. This forces them to mix and they break up into little droplets. In practice, it can be pretty hard. One of the practical challenges is that it takes a stable flow rate to make homogeneous droplets. It can be a big challenge to get a stable flow. That’s especially true if your microfluidic chip is made of a stretchy material (I’m looking at you PDMS). It makes sense to move to a chip that doesn’t stretch at all like acrylic plastic.

I had a great undergraduate come in and work with me this weekend on creating droplets with an acrylic plastic microfluidic chip. I had this working a few months ago but with much bigger channels. My first success was with channels that were more like 1 mm wide. The droplets were close to 1 mm wide as well.

We set about to optimize a fabrication technique that would make smaller channels and then uses channels to make droplets. After much difficulty, we have succeeded. We are now making channels that are approximately 100 µm wide and making droplets that are approximately 50 µm wide.

2017-03-27 06_35_38-Presentation1 - PowerPoint

If you have an application that requires non-stretching microfluidic channels, please get in touch. We can send you one.

Here are parts 1 2 3 4, and 5.

The difference between utopia and dystopia is doing the dishes

I believe in public funding for science and especially revolutionary, high-risk/high-reward projects.  Most of those projects will fail. That scares the funding agencies. It looks like a lot of wasted money. But I think that’s the price for innovation.

2017-03-23 07_07_42-Krita

We need to fill the beginning of the pipeline with lots of good ideas. When something works, there will be plenty of motivation to move it down the pipe. There are big rewards at the end of the pipe. I think that’s great. I just want there to be more support at the beginning.

For projects that do have support (and not necessarily government support), I also see the little human weaknesses as a real problem holding back important projects. The two projects that come to mind are Open Source Ecology and Paul Wheaton’s Permaculture community.

This article (brilliantly titled The Post-Apocalypse Survival Machine Nerd Farm) reminded me of what it was like to live with roommates. Not everyone is equally motivated. Not everyone wants to volunteer their hours getting up early to build a DIY tractor. And not everyone knows that about themselves. It sounds amazing: sustainable agriculture, technical puzzles, building great things, sharing new technology with the world… Utopia! But the reality is pooping in a bucket and getting up at 6AM to troubleshoot a burst hydraulic line.

The Permies community ran into a similar issue. The Wheaton Labs Farm invited a bunch of people to come out and live and plant and experiment with sustainable agriculture. But people didn’t want to do dishes or do the hand towel laundry. A lot of the unsustainable parts of our culture are a direct result of our coping with these little irresponsible things. Why use paper plates and paper towels? Because nobody wants to take care of the dishes and laundry.

The bottom line is that there are natural resources and technology… but getting people to cooperate and do the unpleasant work is the hard part. That’s no surprise, I suppose. It’s just funny that the difference between utopia and dystopia… at the micro level… is  doing the dishes.



Utopian communities sharing their experiences online

I get the impression that there are not all that many people interested in Utopia (as a concept). Maybe we’re a bit more skeptical than folks were in the 1800s. Or maybe charismatic leaders just don’t gain so much traction in an era with electronic criminal records and background checks.

The good parts of living with room mates were really good. A built in social network and a always-on source of good conversation and affirmation? Yeah. Doing other peoples’ dishes… not so much.

I follow three projects with utopian visions:

Open Source Ecology

Paul Wheaton’s Permaculture community

Focus Fusion

I love that these folks are putting their experiences out there. It’s exciting to see folks trying to build something grand. It’s even interesting to watch the setbacks. I don’t know how much popular interest there is in this kind of thing.




6 Month Review of the Scrum Method

The Allen Lab has using the Scrum method for 6 months. It is been remarkably productive. With two graduate students and three undergrads, we produced the data for two papers. One paper was submitted and provisionally accepted. The other is in preparation. We also produced a grant application.

The Allen Lab Scrum BoradThe Allen Lab Scrum Board

I give a lot of the credit for this to the Scrum method. I am new to lab management. My graduate students are very young and my undergraduates are just getting started. They have done amazingly and deserve the rest of the credit. I was not as productive in graduate school or in my postdoctoral work. I produced one paper per year (which is not bad) but this has been eye-opening.

It’s actually very difficult not to try to “convert” people. I feel almost like Scrum is a religion or something. I keep thinking about promoting this to other people in the department. I really don’t think that’s appropriate, so I keep my mouth shut. I’m the new kid and I am not a management consultant by any means. Every lab is different. I recognize all of this. Even so, I rather wish that I had trained in Scrum when I was a graduate student.

Maybe it would not have made much of a difference: there wasn’t a lot of “team science” when I was in graduate school. I don’t know if that’s a good thing or not. Maybe graduate students need more practice in team management. On the other hand, maybe it’s better to learn to do everything yourself. I don’t have a good answer for that, but I know what’s productive in my lab.

Nuclear reactor for efficient conversion of Tar Sands

I have said for years that Canada would eventually use nuclear energy to process the tar sands. It looks like Toshiba is going to make it happen. Converting tar sand to useful oil takes a lot of energy. Since there’s lots of tar on site, that’s the source of energy. A significant fraction of the energy in the tar goes into processing instead of into the consumer’s gas tank. Putting a nuclear reactor on site means that the processing energy comes from uranium instead. In some sense, it’s a conversion of uranium energy into hydrocarbon energy.

Of course, from a climate standpoint, it could be better. We could convert uranium energy (or solar energy!) into converting carbon dioxide into fuel instead of converting tar sand into fuel. But tar sand is a much more concentrated carbon source than the atmosphere.

What I think it really interesting is the funding model. Buy a nuclear reactor and plug it into your plant. That saves energy so you don’t have to burn your fuel on site. That frees up fuel for sale which pays for the reactor. How long before countries without tar sands figure it’s worth their money to convert other resources (e.g. biomass, municipal waste, natural gas) to fuel?