Team:Cambridge/Experiments/Thin Films



See youtube videos of our thin films here.

We conducted a number of experiments with the thin films, outlined below.


Reflectin Thin Films I

  • Description of the basic method
  • Colourful thin films created with reflectin & HFIP
    • Thin film colour not uniform
  • HFIP thin film control did not show structural colour

Reflectin Thin Films II

  • Method refined in an attempt to reduce impurities
  • Bovine Serum Album (BVA) control to test whether generic proteinacious thin films produce colour
    • Did not show structural colour
  • Reflectin thin films appear to crystalize on drying

Reflectin Thin Films III

  • Control indicates that Urea may be to blame for thin film crystalization
  • More controls show that neither GFP nor BSA exhibit structural colour when spun into thin films

Colour Intense Films - First Breakthrough

  • Less is more - using the same concentration, spinning a small volume leads to better wetting and more colour intense films
  • Introducing the 'Piranha solution' for surface cleaning

Uniform Films and Multilayers

  • Quality over quantity - purer reflectin and greater control over spin lead to colour uniformity
  • Attempts to create multilayers with alternating PDMS and reflectin.
  • Problems with stability of reflectin due to impurities hinder progress but produce 'protein art'

Attempts to increase film stability lead to first stable multilayer

  • Dilution and centrifuging of samples and using only the very top layer seem to provide better stability for urea containing reflectin
  • Dialysed protein seemed to be more stable however suffers from dewetting

Spectral Measurements of Thin Films

  • Spectral measurements of single, double and triple refectin-PDMS layers and PDMS control with video footage
  • Film swelling and colour changes induced by breathing due to reflectin layers illustrating the tunability of reflectin