Science at the Speed of Thought - Ambient Intelligence for Scientific Discovery - page 19

navigation and menu-based interaction techniques. Particularly useful is the in-
teractive clipping described above. Transparency and lighting remain very im-
portant elements of visualization methods used in this project.

3.3 Smart Gel

NIST scientists and collaborators are using the Virtual Laboratory to study
smart gels , which might someday be used to make exotic foods, cosmetics,
medicines, sensors, and other technological devices. Smart gels are inexpensive
materials that expand or contract in response to external stimuli. This property
could be useful in applications such as an artificial pancreas that releases insulin
inside the body in response to high sugar levels. Scientists need to understand
how the molecules in these materials behave in order to utilize them in new
products.
For this project NIST scientists are studying a subclass of these materials
called shake gels . Through some complex and as yet unknown process, these
watery mixtures of clays and polymers firm up into gels when shaken, and then
relax again to the liquid phase after some time has passed. A shake gel might be
used, for example, in shock absorbers for cars. The material would generally be a
liquid but would form a gel when the car drove over a pothole; the gel thickness
would adjust automatically to the weight of the car and the size of the pothole.
The VL helped the scientists see that it is the polymer's oxygen atoms,
instead of the hydrogen atoms as previously thought, that attach to the clay.
The team has also made theoretical calculations that may help to explain why
and how the components of the liquid mixture bind together into a semisolid
form. Electrical charges affect the binding process, resulting in water binding to
clay surfaces in a perpendicular arrangement,whichisbelievedtohelpcreatethe
firmness of the gel. Theoretical aspects of the smart gels research are discussed
in [43]. The work is sponsored by Kraft Foods and involves scientists from NIST,
Los Alamos National Laboratory, and Harvard University.
The data provided by the researcher consisted of position data for a collection
of atoms over a series of time steps. We created two visual representations from
these data. The first depicts stick figure representations of the molecules. Bonds
between atoms are derived from proximity of the atoms and the atoms are colored
by element. The time series is shown by animating the motion of the atoms and
bonds. Figure 14 shows a still frame from this representation.
The second representation draws paths for the atoms as they move over
the course of the time series. Each path is shown as connected line segments.
The color of the each path indicates the element. In this representation, the
movement of atoms over time is represented within a static scene rather than by
an animation. Figure 15 shows the path representation of the data.
Note that the two different representations can be used together. When both
representations are turned on, the immersive display provides both an atom's
motion and its history.
User interactions consist largely of menu interactions; these were imple-
mented within our existing general purpose immersive display utility with menu