Still obviously a prototype, shown above the controller V 2, plastic case, arduino uno, 16×2 lcd analog display, soldered wirewrap construction. This unit is used for all versions of the sample holder assembly. V1 -300ml jar following Bo Yang et al., v2 3ml cuvette experiment, v3 3 ml cuvette holder using scavanged HP cuvette holder. v4 3 ml laser cut cuvette holder outsourced to Ponoko for material and laser cutting. (updated 26 may 2017).