Anti-Icing LED Light Covers for Railroad Safety

University  University of Nebraska-Lincoln (UNL)
Principal Investigators  Dennis Alexander, PhD., Kingery Engineering (PI)
Craig Zuhlke, PhD., Electrical and Computer Engineering (Co-PI)
PI Contact Information  202N SEC
Lincoln: City Campus
Office (402) 472-3091 
Funding Source(s) and Amounts Provided (by each agency or organization)  UTCRS (USDOT UTC Program): $72,250
NE Department of Roads: $36,125
Total Project Cost  $108,375
Agency ID or Contract Number  DTRT13-G-UTC59
Start and End Dates October 2016 - June 2018
Brief Description of Research Project  During winter weather conditions snow and ice can accumulate on railroad traffic signal lenses especially when high efficiency light emitting diodes are used as the light source making them hazardous as signals for the engineers. Railroad signal lens polycarbonate (PC) was functionalized to be anti-wetting and anti-icing using femtosecond laser surface processing (FLSP) directly as well as by imprinting PC using a FLSP tungsten carbide (WC) die to produce micron and nanoscale roughness on the surface that is characteristic of anti-wetting surfaces. The micron and nanoscale surface structure on FLSP PC was controlled by adjusting the fluence per laser pulse and number of pulses impinging upon the sample. During stamping applied pressure, temperature, and stamp morphology influenced the imprinted surface structure. Through contact angle measurements, condensation freezing experiments, and placing samples in outdoor icing conditions we demonstrate that both directly processing PC using FLSP and imprinting an FLSP WC surface onto PC enhances the anti-wetting and anti-icing properties. Laboratory scales experiments have shown that the quality of the lens is not affected by the FLSP processing. The next step is to proceed to actual railroad test bed experiments.
Keywords railroad safety, anti-icing, femtosecond laser surface processing, icing of traffic signals using LED lighting 
Describe Implementation of Research Outcomes (or why not implemented) Place Any Photos Here See Report.
Impacts/Benefits of Implementation (actual, not anticipated) See Report.
Project Website