UX & Interaction Designer


Helping female-identifying women feel and be safer when walking alone


Teaching children the basics of electronics through wearable jewelry


We designed CharmBits in order to encourage children to creatively collaborate with their parents and friends while simultaneously exposing themselves to STEM discipline-related concepts. Current market solutions do not appeal or aren’t appropriate for young children. We aim to fill this gap while preserving the power of self-expression.

CharmBits are able to physically come together in a multitude of creative ways and incorporate internal electronics that expose children to how circuits are constructed. In order to enable children to create jewelry using our modular embedded “charms,” CharmBits are flexible; circuits should be able to be formed into loops, for instance. These CharmBits connect robustly enough to keep up with the active lifestyle of children. In addition to the physical CharmBits, we designed and developed a companion iOS application intended to teach children how to build their circuit jewelry through storytelling.

My primary tole on this team was to assist my teammates i prototyping endeavors and to identify constraints imposed on our project – primarily due to the need to engage in physical fabrication – and managing the dependencies born out of said constraints. I was also tasked with examining similar existing products in an effort to identify the pros and cons of said products, understand why the designers of those products made particular decisions, and think of ways to improve or expand upon those designs in order to make CharmBits a successful product. 


Interactive Device Design, University of California, Berkeley


Product Manager, UX/Interaction Designer, iOS Developer

Team Members

Doug Cook — Embedded Systems Designer, Hardware Designer
Elizabeth Lin — Visual Designer, UX/Interaction Designer, iOS Developer
Ian Shain — 3D Modeling, Mechanical Designer


~10 weeks (August 2014 - December 2014)

Key Activities

Ideation, competitive analysis, contextual inquiry, visual design, sketching, storyboarding, digital mockup creation (Sketch, Illustrator), laser cutting, 3D printing, CAD modeling, vinyl cutting, laser cutting, LPKF circuit board construction
•       •       •

Primary Research


contextual inquiry

We also conducted a contextual inquiry at a local elementary school with a science teacher. We believed that an educator could provide insight into the teaching styles that are most effective for imparting knowledge to young children. We learned the following through our conversation with this teacher:

  • Children’s proficiency with a certain topic increases through hands-on learning. Tangible, manipulatable objects make concepts more robust in the minds of children, especially when this is coupled with teacher support over longer periods of time. 
  • It is too difficult for a single teacher to actively engage each student during a single class period. As such, parents will be better able to provide the attention that children need in order to gain the most from a toy like CharmBits. 

Our target audience consists of children in primary school, that is, children between 2nd and 6th grade. In order to better understand this user population, we began our research with an observation activity at the "Tinkering Studio" located in the San Francisco Exploratorium, in which we gained the following insights:

  • Most of the components in these exhibits were fairly large, comparable to the size of a smart phone. This seemed to be an attempt to mitigate the fact that children have a hard time holding and manipulating very small components. 
  • Most children played with the exhibits without reading any instructions. In fact, most of the instructions were placed on a higher surface only viewable by adults. Parents were generally present to explain to their child which pieces needed to connect in order to create a working circuit. 
  Observations were conducted at the "Tinkering Studio" at the Exploratorium, a "public learning laboratory" located in San Francisco.

Observations were conducted at the "Tinkering Studio" at the Exploratorium, a "public learning laboratory" located in San Francisco.

•       •       •

Competitive analysis

I led a competitive analysis of existing products aimed towards teaching children STEM concepts. The goal of this exercise was to identify competitor’s target user groups, product functionality, and usability in order to determine how our product could improve upon or avoid issues inherent to existing products. By identifying competitor strengths and weaknesses, we were able to better define CharmBits’s value proposition. I reviewed the following products

  • GoldieBlox
  • Roominate
  • LittleBits
  • Snap Circuits
  • Sifteo
  • MaKey MaKey
  • San Francisco Exploratorium's "Tinkering Studio"
•       •       •


 Storyboards demonstrating the tasks we intended for CharmBits to support.

Storyboards demonstrating the tasks we intended for CharmBits to support.


We identified the following tasks as being crucial to the success of our product:

  • Parent educating child  —  This task aims to give parents educational tools to help guide a child's learning
  • Child-to-child collaboration  —  This task involves allowing kids to play together and combine their CharmBits while allowing parents to separate the CharmBits back into their respective owner's hands.
  • Child learning individual component functions    This tasks involves teaching children the purpose of individual circuit components (for example, a resistor can be used to limit current flow).
  • Identify parts  —  This task is to identify the name and function of each circuit component based on symbols and connections. 
  • Saving CharmBit design  —  This task is to save work in progress or finish creation for use later. 
•       •       •


CharmBits are modular cells that light up as they are connected or disconnected from “circuits” on the wristband. The band not only provides the CharmBit circuits with power, but its flexibility also allows users to wear their finished product as a piece of jewelry.


The modules connect to clasps on a silicone band. Power and logic connections are provided via spring-loaded pins.

Each individual CharmBits contains a single core ARM microprocessor and tricolor LED. Each component communicates with its neighbors via serial; this decision was motivated by a desire to keep children away from dangerous components, such as capacitors that have the potential to short circuit.

  Triple-axis accelerometer and custom circuit boards, which were created using an LPKF machine

Triple-axis accelerometer and custom circuit boards, which were created using an LPKF machine

  CharmBits connected along the "wearable" band.

CharmBits connected along the "wearable" band.

•       •       •

User Interface

Because CharmBits are intended for use by children and their parents, who may have limited knowledge regarding circuit assembly, we wanted to create visual images that were able to impart meaningful information without using traditional schematic symbols for components like resistors. We wanted CharmBits to have “kid-friendly” icons. This informed the creation of our companion iPad application. Elizabeth and I attempted to create storybook-like lesson plans in order to engage children. We both had experience creating Android applications, but had never programmed using Swift. Before writing any iOS code, we created a prototype in order to gain an understanding of potential user flows. 

charmbits ipad1.png
charmbits ipad3.png
  The iPad application gives children the ability to create circuits, and save the circuit configuration for future examination.

The iPad application gives children the ability to create circuits, and save the circuit configuration for future examination.


User flow diagram of the final CharmBits companion iPad app.

•       •       •


We scoped this project to be wearable, which dictated that our modules be quite small. Fitting all the hardware into these small modules proved quite challenging. We also would have liked to mold our parts, as 3D printing our parts led to more brittle and less attractive pieces. We would have also liked to create a flexible PCB to mount into our band, as the wires created a bulky and rigid band.

The purpose of this course was to learn concepts and skills required to design, prototype, and fabricate interactive devices, that is, physical objects that intelligently respond to user input and enable new types of interactions. We were not tasked with conducting usability testing once our prototype was completed. If I were able to continue working on this project, I would have been interested in testing our product and iterating upon it based on insights gained from research.

Finally, we believed CharmBits had viability beyond just the classroom, and we put together a proposed business plan. The entirety of the business plan can be viewed here.