An Irish company is actively investigating potential
applications in medical devices for a novel conductive polymer that changes
volume and other properties in response to an electrical stimulus.
Potential applications include:
- minimally invasive devices with enhanced
maneuverability, such as guidewires, catheters and leads,
- delivery and retrieval devices, such as embolic
coils used for implant detachment,
- microsurgical tools for ophthalmic surgery,
neurosurgery or fetal surgery, and
- conducting polymer coatings for
"In terms of commercial applications of Micromuscle, there
are currently no FDA-approved devices incorporating the technology, but there
are a number of applications currently being researched," says Maura Leahy,
marketing manager for Creganna,
a medical device development company based in Galway, Ireland.
The underlying technology is based on electroactive polymers
developed by the University of LinkÃ¶ping in Sweden. The polymers swell and
contract as ions and water enter the polymer when a small voltage (typically
1-2V) is applied. When the voltage is removed or reversed, the polymer
contracts and resumes its original shape.
The bulk volume change of the polymer forms a swelling
"volumetric" actuator, in one of the potential uses. In some
instances, the polymer may be attached to a metal. An electric current would
cause the entire structure to bend.
Creganna recently acquired the patents for the technology
from Micromuscle AB of Sweden after the withdrawal of a venture capitalist
forced the Swedish company to seek voluntary liquidation.
Micromuscle was founded in 2000 as a spin-off from leading
research on conducting polymers at LinkÃ¶ping
University. The main
shareholders of Micromuscle were Industrifonden, CIMON Medical and Iteksa
One of the key patents for the technology, "Micro
tools", was granted by the U.S. Patent Office on Feb. 19, 2008. The electroactive
polymers used by Micromuscle are from the group consisting of pyrrole, aniline,
thiophene, para-phenylene, vinylene and phenylene polymer. The discovery of electrically
conductive polymers was awarded the Nobel Prize in 2000. Micromuscle is described
as the most advanced application of the technology for the medical device
arena, particularly for minimally invasive therapies.