# How Can You Engineer Ice Crystals?

## Biomolecular engineer Barbara Wyslouzil explains how supercooling water allowed her to create ice cubic, rather than hexagonal ice crystals

Vocabulary: crystal structure, cubic, supercooled water, vapor, condensation,

Next Generation Science Standards: PS1.A: Structure and properties of matter, SEP 2: Developing and Using Models , and CC1: Patterns. Can be used to build towards the following performance expectations: MS-PS1–4, and HS-PS1–3.

Common Core State Standards: CCSS.ELA-LITERACY.RI.6.1, CCSS.ELA-LITERACY.RI.7.1, CCSS.ELA-LITERACY.RI.8.1, CCSS.ELA-LITERACY.RI.9–10.1, CCSS.ELA-LITERACY.RI.11–12.1

Did you know that not all ice is created equal? The stuff that solidifies in your freezer, as well as almost all natural forms of snow and ice on earth, is called hexagonal ice, so-named for the pattern the crystals form as they take shape. But there’s also cubic ice, a very rare form of ice that occurs naturally only in earth’s upper atmosphere. In the lab, cubic ice can only be made by quickly supercooling water to a very low temperature, essentially “tricking” the crystals into arranging themselves into a cubed pattern.

Barbara Wyslouzil, a professor of chemical and biomolecular engineering at Ohio State University, came as close as any scientist has come to creating perfectly cubed ice. She joins Ira to talk about the properties of cubic ice and why we study it.

Print this segment transcript.

### Questions

• Where did researchers first discover cubic ice? How did they know that cubic ice was present?
• In Barbara Wyslouzil’s description of how her lab created cubic ice, she describes the phases of matter (solid, liquid, or gas) of the water in each step. Sketch a flow chart of the process, indicating the water’s phase of matter in each step.
• Why is it so difficult to observe cubic ice? Provide at least three reasons why cubic ice is more difficult to observe than regular hexagonal ice based on Dr. Wyslouzil’s description.
• What special technologies does Dr. Wyslouzil have to use in order to even observe the cubic ice that her lab creates?
• Dr. Wyslouzil describes several places where cubic ice might exist naturally in our universe —why does she think that cubic ice could exist in those places? What do those places have in common?

### Activity Suggestions

• Have students experiment with the properties of supercooled water by freezing bottled water and creating instant ice or supercooled fruit pops. Have students compare the shape of ice crystals formed through different methods freezing — which methods create jagged or cloudy ice, which methods create smooth or clear ice?
• Participate in Science Friday’s Science Club — invite your students to engineer something frozen — it could be a new dessert, a special contraption for staying cool in the summer, or even some form of ice art. Learn more at ScienceFriday.com/scienceclub