Week 1_Spring (From Christmas break to 1/22/2018)

Team FlowRiders is beginning the year with new designs, equipment, and research.

Updated Ridge Design 

The ridge design for the disc has been updated. Changed are intended to better facilitate flow while reducing tissue stress.

Note that the positive pressure gradient increases slowly, but negative pressure gradient is steep.

 It also smoothly tapers toward the center for a minimally-regressive pressure gradient as it rotates.

Gelatin-Tissue Model

A ballistic gelatin was made to have similar mechanical properties as human tissue. The outer surface was mildly burned in the cooking process, but the bulk mechanical properties are unaffected.

This will be permeated with tubing to test the device's flow generation. As the device rotates underneath the gelatin, with sufficient weight on top, the flow of water through the tubes will be measures. This experiment will not be completely anatomically accurate, since the 3/16 & 1/4 in ID tubing diameter is too large by about 3 orders of magnitude and its plasticity and compliance have not been taken into account, but it may give a sense of the device's viability.

Soft Pressure Measuring Pad

A pressure sensing pad is in the process of being ordered through Blue Chip Medical Products, Inc. A request for a quote has been submitted.

Disk and Fabric Interface Research

From the website massage chair report (source: https://massagechairreport.com/how-does-a-massage-chair-work), it discusses how a massage chair works and the imperative functionality of the back support roller massagers. In this website, it states vaguely that a nonfiction strong material is used for the rollers so that it does not wrinkle or cause too much friction with the textile of the back-support of the chair. Researching such descriptive materials Teflon (polytetrafluoroethylene) was found to have such properties. 

Moreover, Teflon's characteristics are described as follows through the Wikipedia website:

PTFE is a fluorocarbon solid, as it is a high-molecular-weight compound consisting wholly of carbon and fluorine. PTFE is hydrophobic: neither water nor water-containing substances wet PTFE, as fluorocarbons demonstrate mitigated London dispersion forces due to the high electronegativity of fluorine. PTFE has one of the lowest coefficients of friction of any solid.

Furthermore it describes the textile of the back-support of the chair to be of synthetic leather material which mostly consists of polyvinyl chloride material. This material has enough strength and flexibility to work well with the massage rollers.