Cindy Harnett

Assoc Professor

Am an associate prof in Electrical and Computer Eng, came to U of L in 2006, was previously at Sandia National Laboratories (CA) for four years, before that was a postdoc/Ph.D. student in the Applied and Engineering Physics program at Cornell University.


  • Ph.D. in Applied & Engineering Physics, Cornell University, 2000
  • B.S. in Physics, Harvey Mudd College, 1993


Controlling Thermoplastic Elastomer Optical Properties by Mechanical Processing- 2019

We demonstrate that the extrusion speed of thermoplastic urethane elastomer can modify its optical transmission by a factor of more than 100. Varying extrusion speed at constant temperature may tune optical properties along the axis of a filament, for example creating absorbent regions that are sensitive to length and diameter changes, surrounded by more transmissive segments that carry the sensor signal over long distances. Such waveguiding in a stretchable optical fiber requires a stretchable cladding with lower refractive index than the core. In experiments toward a rugged, stretchable fiber cladding, we investigated whether solvents could modify the outer structure of the filaments. Soaking the filaments in NMP (n-methyl-2-pyrrolidone), then stretching the filaments while the solvent dried, turned out to modify the filaments in a way that solvents alone did not, creating porosity and reducing the appearance of optical clarity.

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