Lickometer
The lickometer measures the precise time of lick events, and provides a steel tube to deliver liquid reward.
The lickometer uses a photogate created from an infrared emitter with a narrow (10 degree) beam angle and a spectrally matched phototransistor. A white LED angled towards the subject is provided, to be used as a cue or for feedback.
The lickometer interfaces with the state machine via the port interface board.
The lickometer design file contains two 3D printable parts:
a scaffolding to hold the LED, sensor, emitter and 15ga drink tube
a sheath to block ambient light and to mount the lickometer.
When printed with an FDM printer using a 0.4mm extruder, the components press-fit into the scaffolding, and the sheath press-fits over it.
The lickometer shown above was printed from gray ColorFabb XT Copolyester.
A 4-40 nut press-fits into a pocket in the sheath, to mount it to a ThorLabs mini-series post.
Print settings are specified in a text document that accompanies the design files on Github.
The mount shown in the images above provides coarse adjustment in 3 axes, and rotation about 2 axes. Its components are:
1 Imperial MS series post (MS3R shown; 6mm mini-series post with 4-40 threaded end; choose length to match your assay)
1 RA90TR (1/2" to 6mm post clamp)
1 Imperial 1/2" optical post (TR2 shown, choose length to match your assay)
1 Imperial 1/2" post holder (PH2 shown, choose length to match your assay)
1 Imperial BA1S mounting base
The bill of materials for the lickometer is shown below:
