I. Input Subsystem: Feeding and Cleansing.


This subsystem is the input system of the complete automated device and consists of three operational steps:

  1. Cleansing the larvae entirely of the initial food medium;
  2. Depositing new food medium for controlled feeding time;
  3. Cleansing the larvae entirely of the secondary food medium.

The two main constraints of the first subsystem design include:

  1. Maintain an adequate environment for living specimen;
  2. Reduce handling and time required to execute steps 2-4;

The final design exists as a central circular well-plate that rotates beneath three dispensing stations: 2 washing stations and 1 feeding station. The transfer method of rotation allows feeding and washing steps to be executed simultaneously in one full rotation of a single specimen well-plate. The central rotation unit also conveniently allows future integration of the camera station within Subsystem 2.

The first egg feeding step currently performed at NEMC is a manual operation, and will take place outside of the system. The remaining three steps are automated by the prototype. The following outline illustrates the manual and automatic processes of the design solution:

Manual:
1. Fill well plate of fruit fly eggs in pure yeast medium, approximately 10 larvae per well. Store plate for three days to allow development to third instar stage. Place plate on rotation unit.
2. Enter genetic line type to corresponding location on PC control program. Press ‘Go’ to begin automation.

Automatic:
1. Plate rotates one full rotation where each well undergoes a wash, wash, and feed sequence.
2. Rotation stops for 30-minute feeding period.
3. Plate rotates one full rotation and each well undergoes a wash, wash, and snap image sequence.
4. Images are stored and data analysis performed, as detailed under Subsystem 2.


Initial prototype of automated fruit fly cleansing and feeding system.

Each component of the prototyped feeding and cleansing subsystem are captured below:


Custom fabricated well plate with 16 mesh bottomed vials in which the fruit fly larvae are housed.


Rotary table (10 in x10 in) and stepper motor are used to rotate the well-plate through cleansing and feeding stages.


Three liquid reservoirs and the dispensing solenoid valves for the cleansing water and food medium.


Drainage system to prevent the cleansing water from destroying the rotary table.


Front panel of PC program that controls the rotation system and solenoid valves.