This
image is a
photograph
of a pattern of copper ions in a hydrogel. Anodizing a penny (copper) in
contact with a negatively charged polyelectrolyte hydrogel creates the pattern.
These
patterned regions have several interesting implications:
1. It
creates patterns of ions (so-called ‘ionoprinting’)
that are stable in water. Patterned ions
may be useful as tools for studying biology (e.g., Ca ions are critical in
biology).
2. It
replicates topographical features, which may be useful for creating soft
lithographic stamps.
3. It
generates stress that can be utilized for actuation, which may be useful for
soft robotics (i.e., robots that have mechanical properties similar to human
flesh).
4. It
changes the modulus of the material by an order of magnitude; this attribute may be useful for tuning the
mechanical properties of materials on demand.
5. It
is reversible by extracting the copper ions.
