The Problem

​The lab needed an improved electrospinning apparatus for the creation of piezoelectric film for use in a digital stethoscope. The old setup (shown below) did not allow for careful control of all the spinning parameters such as humidity, spinning speed and electrical insulation of the system from its surroundings.

Requirements

• ​Enclosure to control humidity
• All electrically conductive components inside enclosure other than collector drum must be covered with insulating material
• 6” metal collector drum must spin smoothly at 3000 rpm with minimal vibration
• Needle must move from side to side in a slot in side of enclosure
• Distance between needle and drum must be adjustable
• Budget: $2000

Sketching

First Iteration

Support parts wouldn’t have held grounding brush in ideal location, and motor bracket would have been difficult to mount.

Second Iteration

Acrylic enclosure design was modified to allow the 3D printed supports to sit outside the enclosure, eliminating the need for the parts to cover the bearings and motor. Still, parts to be 3D printed would have required too much material, costing $250 to print.

Final Design

Thinner, shelled parts cost only $100 to print while maintaining strength. Once I finalized the support parts, I designed an acrylic enclosure to slide between them, allowing for climate control as well as easy operator access and viewing.

​I fabricated the enclosure using a laser cutter, then mounted everything on an ABS sheet with rubber feet on the bottom to dampen vibrations. I also designed other parts of this apparatus such as the flanges for the drum collector and the plate to connect the pump to the linear actuator. The new setup works very well.