titlefigur8.JPG

IMU Sensor Case

Movement Intelligence.

Overview

Company

Position

Roles

Period

Skills

Link

Impact

Figur8

Mechanical Engineering Intern

Manufacturing Testing, Mechanical Design, User Experience Design, Project Management

June - Aug 2018

Human-Centered Design, Product Design, 3D Printing, Arduino, Python, SolidWorks - CAD

https://figur8tech.com/

Currently being mass manufactured by Figur8 and launched as accessory with the FlexTech Sensor

Objective

This summer, I worked with a startup, Figur8, which seeks to digitize 3D body movement easily for everyone. The IMU sensor is encased in a rectangular shape, and one of the projects I worked on was to develop a new hardware attachment that could place the sensor on different parts of the body. A hardware attachment needed to be made that securely holds the sensor to one's arm, shoe, wrist, and hip. This project was done in collaboration with a UX/Product Design Intern from the Rhode Island School of Design.

Approach

Since the same sensor was going to be used to for various locations on the body, I decided to design a base 3D model that can be edited easily to transform it into different iterations to perform different functions. The base model has four corners that contour to the sensor and works as a press fit to hold the sensor in place.

 

The design was first 3D printed (FDM) for it's quick prototyping speed. Finalized versions of the harness were printed with Formlabs printers (SLA) in order to take advantage of a flexible resin for the user to easily snap on and off the sensor.

Ideation

During the ideation phase, multiple case and holding mechanisms were considered. Below are some different iterations.

ideation.JPG
The "Base"
Design

The base was designed to have as many features as possible that could translate to all different harnesses for the different body parts. The main similarity between all the harnesses was the way the sensor was held in the harness itself: the flanges at the corner.

 

 

 

 

 

 

 

 

 

 

 

 

The base was created based on the user-centered design. Important considerations when designing this was:

  • the user would be taking the sensor in and out of the case quite often

    • before and after each workout to charge the device​

  • the device needs to be secure on in the case and on the person to read data

    • shaky/unpredictable movements from physical activity

To the right are an isometric view and a side view of what the base model looks like. Below are the different iterations it took to decide on how the harness would hold the sensor. Overtime, the design starts off being more flush to the sensor and eventually the fringes curve and flare outwards.

base_1.PNG
base_2.PNG
wrist top.jpg

Iterations Chronologically

Release
Mechanism

When considering user feedback and observing the IMU sensor case in action, I noticed that the user would often have to release the sensor from the casing in order to switch hardware harnesses. This resulted in designing the case to snap fit to the sensor so that the user can insert and remove the sensor easily and multiple times. For each body location, the release mechanism for that harness is a little different. It's similar where on opposite sides of each harness, I have a few indent/holes that the user can use to grip the actual sensor itself to push the sensor out of the harness. 

At the top of the 4 corners of the casing are fringes that extend outward for the user to have a better hold on the casing itself. This way, the sensor can easily pop out when the sensor is being pushed out through the holes. In order to make the fringes very comfortable for the user, The flanges widen out and flatten horizontally to provide more area for the user to grip the harness when extracting the sensor out.

 

Below is a gallery of the 4 different harnesses and a description of how they are used.

Scroll Right
Arm Band

Arm Band

The horizontal slit case is used for the arm band.

release mechanism_crop

release mechanism_crop

The release mechanism includes a hole for your finger to have access to push the sensor.

hip_crop

hip_crop

The vertical clip is used for the hip clip.

wrist_crop

wrist_crop

The vertical slit case is used for the wrist band.

shoe_crop

shoe_crop

The horizontal clip is used for the shoe clip.