SloMo Safety Video

The first safety video is out! In a demo conducted by our supplier, we can observe the stress distribution that occurs when a concrete chisel is dropped from a height of 10 cm. This height is certainly sufficient to break skin. we hope to obtain enough funding to purchase a camera like this to observe impacts on the body from tools, projectiles, falling objects, electricity, etc. It is amazing the detail that you can see in these videos.

Check out the YouTube video here

Using the mold and embedding blood bladder and bones

Now that the reusable mold is complete, it was time to try it out. We learned the hard way that the mold needs to stay very rigid. We ended up having serious leaks around the edges due to the compression of the straps. The hand was mediocre but we learned a whole lot in the process. The next pour should go more smoothly.

The hand is a little off kilter but has an embedded blood bladder and bones. If we can get the mold set up correctly, I think we have a suitable process. Interestingly, when we were cleaning up the damaged hand we realized that the hands will be quite difficult to cut with a box cutter and may even be difficult to pierce. We will have to test them and find out.

Some photos from the latest activities:

The mold from our last activities

We poured a small amount. Since the dragon skin mix sticks to itself, we can pour in stages. Once the first stage started to set, we installed the blood bladder and bones.

Kind of cool side-by-side photo. You can start to see how realistic this really is. The bladder and hosing replicate, very accurately, the Radial Artery.

Once the first layer of dragon skin has cured, we installed the top half of the mold and reassembled part of the plexiglass casing. Unfortunately, we learned later that we should have reassembled the whole box. The syringe is for later pumping a blood mixture into the hand's blood bladder.

The mess. The compression straps were too tight and caused a gap to form in the edges of the mold. 

The disaster. With some cleaning up it wasn't a total loss.

The hand didn't turn out too terribly. It can be used for testing but isnt the prettiest thing. This photo shows pumping blood into the blood bladder.

Close-up of a hand with artery and wrist bone. Not too bad.

Success! Making a reusable mold is not the easiest thing to do but we did it!

Our team of three embarked on a more informed journey to create a realistic hand. Using the knowledge gained from our first experiments, we attempted the following process:

1. Cast a negative using alginate
2. Cast a positive with resin (with a wrist this time)
3. Construct a plexiglas box
4. Cover the resin hand half with clay and install acorn nuts
5. Spray all surfaces liberally with mold release
6. Pour silicone rubber in the box to fill the container
7. Once cured, strip the box and remove the clay
8. Level all surfaces, spray with mold release, and pour again
9. Strip the form and yield 2 halves
10. Party

Here are some photos of key moments in this process.

This is our spread. all of the materials needed for the aforementioned steps!

Our team (Alex and Spencer) taking initial measurements

Mixing alginate. This is a 50/50 mix by volume water/alginate powder

Waiting...I had the pleasure of casting my hand in the alginate. It takes about 8 minutes to cure. In the meantime, you must be very still as the alginate/water mixture cures. I was nominated for this task because I have the smallest hands.

Aerial view of Spencer mixing resin. Yes, it was well ventilated!

Pouring the resin with high hopes.

High five! The resin cast worked...very well.

Trimming the excess resin from the wrist. It is strange to cut
a replica of your own wrist.

Resin hand in the Plexiglas box. This was uncharted territory.

Since we need two halves, we must cover up one half with clay before pouring the silicone mold. This was VERY time consuming.

This is the hand half covered in clay. The acorn nuts are to key the surface so the silicone halves fit perfectly when casting in the future.

The resin hand with clay and acorn nuts in the Plexiglas box.

Mixing the silicone rubber for the first half

Mixing parts A and B!

Pouring the silicone rubber...you must be very careful!

The hand once the rubber has been poured and the Plexiglass has been stripped.

We put the box back together, sprayed it all down with mold release, and poured the second half of the silicone rubber over the first half (resin hand stays in place)

This is the final block. It doesn't look like much but...

Once you separate the two halves and the resin hand, you can see that this is a reusable silicone mold. The acorn nuts can be used to help line up the halves. If you look closely, you can see the funnel we made for pouring. The whole purpose of this mold is to be able to later skip the alginate steps and pour many exact copes of a hand for demonstrations. This is important for demos that are aimed at showing the difference in injury with and without gloves, for example.

Learning from mistakes...

Based on ConocoPhllips data, we decided to focus on hand injuries for our first LiveDemo. There are a surprising number of hand injuries related to grinders, box cutters, and falling objects. Logically, that meant we needed to make some super realistic hands for use in demos. Unfortunately, there is little guidance on the web for such things (for good reason, I think). There began our adventure...

On a trip to Boston (on the way to my wedding) we decided to do some initial experiments with lifecasting. Our goal was to make a reusable mold through the following steps:
1. Use alginate to cast a one-time negative of a hand
2. Use a high strength resin to make a positive by pouring the resin directly into the alginate
3. Use the resin positive and plaster to make a reusable negative for later pouring a specially designed mix.

Interestingly, this is how crowns (for teeth) are made by dentists. This is where we got the idea.

The first two steps went very smoothly. Alginate is an interesting material. It is actually found in a lot of foods as a thickening agent. It is extracted from seaweed, absorbs water very quickly, and sets from a liquid to solid in a matter of ~8 mins. It is also safe for the skin and captures very fine detail on the surfaces to which it is exposed. It also smells like candy, which is cool.

This is what the alginate looks like when it has cured.
In this photo the resin has already been poured into the cavity

The resin, while volatile and quite noxious, was easy to mix and pours quickly. We poured the liquid resin directly into the void of the alginate mold and allowed the resin to set for about 1 hour.

This is the resin hand once the alginate has been stripped. 

After an hour, the alginate is stripped and...viola...an incredibly high detailed replica of a hand. The only problem: The resin hand is nothing like a human hand.

Now, for the problematic part. After a few tries we learned quickly that typical plaster will not work for making a reusable mold. The resin sticks and the plaster captures almost no detail.

Resin hand in plaster in our (failed) attempt to make a reusable negative.

We had to stop our experiment there. Since I was getting married in a few days, I needed to divert my attention to flowers, cake, and my fiancee!

Kick off!

We are starting the journey to create the first true Live Learning Laboratory for construction safety. The idea is simple: Most workers do not learn from PowerPoint sing-alongs. Rather, they learn and retain important information better when they see and experience REAL events.

We are targeting three main questions:

1. Can we show people what its like to be injured without actually injuring them?
2. Will live demos improve learning and retention?
3. Will this experience change their perspective of and tolerance for risk?

This project is a partnership between the University of Colorado and ConocoPhillips. Fortunately, our collective team has a wealth of safety management knowledge, we know how workers are being injured, and we are well versed in the theory of effective teaching and learning. We do not yet know how to model injuries in a hyper-realistic manner or how experiential learning impacts risk tolerance and retention. This blog will document our journey to learn LifeCasting, experiential safety demonstration, sensing, high speed videography, and  much more. This blog will also document my journey to learn how to blog.

Hand injuries like this are all too common in our industry! In this project we will start by realistically modeling hand injuries.