From pacemakers constructed of materials that so closely mimic human tissues
that a patient's body can't discern the difference to devices that bypass injured
spinal cords to restore movement to paralyzed limbs, the possibilities presented
by organic electronics read like something from a science fiction novel.
John D. Tovar, assistant professor of chemistry at The Johns Hopkins University. Credit: Will Kirk/JHU
Derived from carbon-based compounds (hence the term "organic"), these
"soft" electronic materials are valued as lightweight, flexible, easily
processed alternatives to "hard" electronics components such as metal
wires or silicon semiconductors. And just as the semiconductor industry is actively
developing smaller and smaller transistors, so, too, are those involved with
organic electronics devising ways to shrink the features of their materials,
so they can be better utilized in bioelectronic applications such as those above.
To this end, a team of chemists at
Johns Hopkins University has created water-soluble electronic materials
that spontaneously assemble themselves into "wires" much narrower
than a human hair. An article about their work was published in a recent issue
of the Journal of the American Chemical Society.
"What's exciting about our materials is that they are of size and scale
that cells can intimately associate with, meaning that they may have built-in
potential for biomedical applications," said John D. Tovar, an assistant
professor in the Department of Chemistry in the Zanvyl Krieger School of Arts
and Sciences. "Can we use these materials to guide electrical current at
the nanoscale? Can we use them to regulate cell-to-cell communication as a prelude
to re-engineering neural networks or damaged spinal cords? These are the kinds
of questions we are looking forward to being able to address and answer in the
The team used the self-assembly principles that underlie the formation of beta-amyloid
plaques, which are the protein deposits often associated with Alzheimer's disease,
as a model for their new material. This raises another possibility: that these
new electronic materials may eventually prove useful for imaging the formation
of these plaques.
"Of course, much research has been done and is still being done to understand
how amyloids form and to prevent or reverse their formation," Tovar said.
"But the process also represents a powerful new pathway to fabricate nanoscale