Measuring reaction rates.

 

To the left is one of our Rapid mixing apparatus prototypes.  This apparatus is designed for measuring chemical or biochemical reaction kinetics.  The prototype drives two syringes that mix reactants which are introduced to a flow cell for spectral analysis.  We have built prototypes with one or two motors.   Prototypes use servo controlled valves to route solution from reservoir to syringes or from syringes to flow cell.

 

The photo below shows an early Z-geometry flow cell.  Solution enters and leaves through standard 1/4" x 28  fittings.  UV-vis absorance is monitored using commercial fiber optic spectrometer and optics.

 

 

 

Microtiter Plate Reader.

 

We are working to develop an optical reader for 96 well microtiter plates.  The figure to the left shows our current setup based on our 3d printed spectrometer.  We have also developed hardware for spectrometers that use fiber optics.  In the figure, you see the plate in the foreground that moves along a track in the Y-direction.  The spectrometer is mounted on 6 mm rails and moves in the X-direction.  The light is provided by one of 8 white leds arrayed along the X-axis, below the spectrometer. 

 

The spectrometer, leds, and xy stage are all controlled by a Teensy 4.1 microcontroller board (figure on lower left).  Incorporation of TMC2209 stepper motor drivers allows sensorless homing, eliminating the need for end stop switches.

I'm going to get back to this.  Right now, we don't have the software refined for the motor drivers and have not really started work on the user interface.

 

 

Isolated Potentiostat for Electrochemical Monitoring of Capillary Electrophoresis.

 

The photo on the upper right shows an instrument we built for a customer who needed an electrochemical detector for capillary electrophoresis.  The instrument needs to be isolated from other instruments / computers / power sources, so we incorporated a raspberry pi zero 2w and powered it using a 7 amp hour, 12 volt sla battery.  The instrument communicates with a host computer over WiFi.