Attempt to build DIY Microvolume Spectrophotometers or Fluorospectrometers to quantitate micro-volumes of sample. Commercial Products like the NanoDrop™ are very popular in scientific labs. The measurement principle of holding a drop between two points - the light source and the sensor - allows to measure samples as small as 0.5µL up to 2µL micro volume without a cuvette. The simple basic principle should be perfect for DIY lab equipment and goes perfectly well with the PublicLab spectrometer concept and SpectraWorkbench software.
So far I built two prototypes from laser cut, black acrylic with mainly a webcam a DVD grating and a mirror inside. The results are promising for measuring absorption spectrum of liquid in the visible. See here for drawing and pictures: http://hackteria.org/wiki/index.php/DIY_NanoDrop
Next steps: I plan to refine some details, hold a workshop at HackteriaLab 2014, document the assembling and upload it together with the design files. An other goal could be to try to measure at lower wavelength (like 260, 280 nm) to quantify DNA and protein. As the lower limit of the DIY spectrometer seems to be around 350 nm I consider using a potodiode rather than a webcam. Not sure on what "transparent" materials to use yet.
As an active member of Hackteria.org International Network for building DIY generic lab equipment and art, I (GaudiLabs, gaudi.ch/GaudiLabs) am experimenting with various DIY lab equipment.
Update: The website is updated with a new version of a laser cut device now called OpenDrop. The files are on GitHub and you are welcome to try. Thank you for all the valuable comments.