EAP Watch: Blink Alert

 

Illustration:  UC Davis

Electroactive Polymers (EAP) are machine materials that respond in shape to an electrical input. There is a wide range to their components and functionality. I've been looking to them in regards to design potential in the world of architectural engineering. Some of the more exciting EAP designs coming to market now are being applied in the medical field, destined (or doomed, depending on your point of view) to vastly expand our bio-mechanical cyborg future.

A press release from UC Davis Health System crossed my desk this morning for an EAP devise in development that can control blink movements for people with paralyzed facial muscles. The innovation over existing blink-repair technologies is that it will require a shorter less invasive procedure, and that if there is a healthy side of the face the EAP system can synchronize with the other eye.

In comparing blink restoration to my own research, it is interesting to think about notions of mediating the transfer of light and information across a barrier. In bioclimatic architecture we're looking to control the flows of energy in and out while maximizing human pleasure--in some cases pleasure might be the view. The parallel of opening and closing is important for both the human organism and the optimized building, and is a central theme in my studies this semester.


From the UC Davis press release:
For their study, Senders and Tollefson used a novel alternative method for eyelid rehabilitation in permanent facial paralysis. They used an eyelid sling mechanism to create an eyelid blink when actuated by an artificial muscle. Using cadavers, the surgeons inserted a sling made of muscle fascia or implantable fabric around the eye. Small titanium screws secured the eyelid sling to the small bones of the eye. The sling was attached to a battery-operated artificial muscle. The artificial muscle device and battery were into a natural hollow or fossa at the temple to disguise its presence. ...

The three-layered artificial muscle was developed by engineers at SRI International of Palo Alto, Calif., in the 1990s. Inside is a piece of soft acrylic or silicon layered with carbon grease. When a current is applied, electrostatic attractions causes the outer layers to pull together and squash the soft center. This motion expands the artificial muscle. The muscle contracts when the charge is removed and flattens the shape of the sling, blinking the eye. When the charge is reactivated, the muscle relaxes and the soft center reverts back to its original shape.