1. Geometry
   1. Current System
      1. Plastic frame
      2. Set-screwed trackways
      3. Emitter
         1. Needle position is not really repeatable or stable
         2. 3 DOF but without reference/measurement markers
         3. Q1: Direct syringe pump-coupling vs. tubing?
         4. Q2: Orientation of needle?
         5. Q3: Distance from collector?
      4. Collector
         1. Position is fixed relative to the needle
         2. Primary mandril is large and heavy
         3. Mountings are slightly off-axis-->warping and bouncing of rods
         4. Q: Move Needle or collector relative to needle?
   2. Ideas
      1. 3-axis CNC-style positioning arrangement
         1. Option 1: Needle moves relative to collector (top-down)
            1. Requires 3-axis (xyz) stage to position needle over the collector
         2. Option 2: Collector moves relative to fixed needle (xyz)
            1. Could use automated microscope stages
         3. Decision: Primarily based on cost...
            1. I already have two micrometer stages(?)
            2. Q: How much precision do we want?
            3. Depends on whether or not we try...
            4. near-field spinning
            5. linear motion of the collector
2. Electrical Field
   1. Current system
      1. Needle + mounting plate become charged
         1. Should get fairly broad field
         2. N.B. dV = E*dist
      2. Collector
         1. Location of the ground: at the end of the axle
            1. Both axles, the whole mandril, and any metal touching become a collector
            2. This alters the shape of the field and confuses the incoming fiber
   2. Ideas: Field Shaping
      1. Ex: The Helicopter Effect with the Downing Chopper
         1. Faster deposition observed when the collector is directly grounded and small
      2. Emitter-side
         1. Flat plate with needle in it vs. Just needle
         2. Clamp directly to needle --> more focused field/cone vs. broad-field region
         3. Q1: Clamp directly or place electrode within solution?
      3. Collector-side
         1. Change the location of the grounding wire.
         2. Pattern collector to get local control of field
         3. Use field-shaping electrodes away from the collector
      4. Summary:
         1. Clip directly to needle/place electrode within solution
         2. Ground directly to collector
         3. Isolate collector from axles
3. Shaped collectors/Field manipulation
   1. Want to be able to tune the shape of the field
   2. Clip directly to needle?
   3. Optimize the placement of the grounding wire
4. Collector Design
   1. Current system
      1. Flat plate
         1. It's flat and platelike.
         2. Could translate plate with respect to needle --> rastered deposition
      2. Rotating Mandril
         1. Theoretically helps with alignment
         2. RPM correlates to fiber alignment
            1. Current motor: 800 RPM
            2. Papers with high alignment can have up to 6000 RPM
         3. Grounded to the entire axle/motor system
         4. Heavy (slower)
      3. Ideas
         1. Translating flat plate/mandril as some papers have
         2. Pattern the collector to shape the field/control where fibers land
         3. Try wire-cage-style collectors vs. metal tubes
         4. Insulate collector from axle
         5. High RPM motor (Downing Chopper)
         6. material: cond/not-->density/porous collector
5. Environmental Factors
   1. Airflow
   2. Ambient fields
6. Biggest concerns?