Alpha Prototype

The team used plastic containers and two different-sized roller balls, one from perfume roller balls, and the other from ballpoint pens. We used the drilling machine in the machine shop and hot glue to secure the parts. 

This was done to get an initial idea about the on-scalp feel and access to the scalp either design might have. While larger roller balls might feel better on-scalp due to reduced pressure at each point, they might not be able to reach the scalp in the first place due to their large size and end up dispensing product on hair instead, killing the entire point of this product.  On the other hand, while smaller, ball-point pen rollers will offer much better access to the scalp due to their smaller size, they will feel uncomfortable to the touch and are capable of only dispensing so much liquid in one go,  drastically reducing the usability of the product to the point where it becomes unviable and uncomfortable to use it. 

This tradeoff between access to the scalp and comfort and usability is one of the major considerations that were part of the equation when the  alpha prototype was made and is one of the main parameters we aim to test with what we have built.

Using a micrometer to measure the diameter of the perfume roller ball and the ball point pens. This measurement will determine the size of holes that need to be drilled in the bottom of our makeshift containers.

Holes in the product body were drilled using a hand drill from the machine shop. A 0.344" bit was used for the perfume rollers, while a 0.11" bit was used for the pen refills. Holes were further widened and smoothened using the 0.11" bit to accommodate the roller stems of either size 

Finally, the ball-bearing rollers were secured to the product body using hot glue to fix the stems and plug any possible leaks. These prototypes, however, are only representative of the form factor of the product and will be used to understand the on-scalp feel when in operation.