PHOTO: M. SCOTT BRAUER. ILLUSTRATIONS: JAY SMITH56 DISCOVERMAGAZINE.COMMaterials selection
The first step to making a functional fiber is to choose the
right materials. Depending on what the fabric will do, these
materials may include insulators, semiconductors and metals
— the basic ingredients of optics and electronics. All of these
must melt at the same temperature so they can be combined
and drawn together.Creating preform
To perform a task, such as lighting up or measuring
vibrations, the fiber’s components need to be organized
very specifically. First, you make a “preform” by rolling
materials into tubes and nesting them in layers. The
core of the preform may be a solid rod made out of one
of the materials, or may be hollow to accommodate
the flow of liquids through the final product. After
assembling the preform, you can add electrodes by
cutting grooves into the sides. These electrodes can
supply an electronic fiber with power or can
collect output from fiber sensors.Drawing Process
Next, you place the preform at the top of a draw tower.
A furnace heats the cylinder while motorized wheels
pinch and pull the bottom end. The tower stretches the
preform — which may be an inch or two in diameter
— into a filament that may be as thin as a hair. You
maintain the preform’s structure by precisely
controlling the temperature and the force
applied to the system. As a result, the
functional fiber retains the same
optical and electronic qualities
even as it’s miniaturized.HOW TO MAKE A FUNCTIONAL FIBER
Greater functionality
can be achieved by
combining multiple
devices in a single fiber.The final fiber is a
miniaturized version
of the preform.After making
its way
through the
draw tower,
this preform
(above) is
transformed
into a spool
of functional
fiber (right).
Final preformAdding
electrodesThermalHeatOpticalAudio
Rolling layers
of insulating
materialSEMICONDUCTORINSULATORMETALFurnaceSpoolerDiameter
gaugePreformDRAW TOWER