Smart Knob - VUI

Have you ever been annoyed by over-cooking food and struggled on conducting multi-tasks while cooking food?

The Smart Knob is an IoT device that transfers your non-digital stove to a smart one. The Smart Knob embed VUI (Voice User Interface) with Amazon Echo, Google home. It is conducive to users' cooking experience by assisting heat control by communicating with it.

Produt Designer

Spring 2018
Individual Project


1. Replace the old knob to the digital one

The Smart Knob is portable and easy to replace for a user who rent appartment.

2. Easy to set up

Once downloaded the supporting app of the Smart Knob on your phone, the smart knob will wake up when you close your phone to it. In the supporting app, it can auto-detect wifi connections.

3. Conversational Interface (Smart Knob + Amazon Echo/ Google Home)

The "Smart Knob" relieve your hands by talking with Echo or google home. It assists you in control stove temperature while cooking.

4. Sync Recipe with Smart Knob

Users can download a recipe from supporting app and sync it with the "Smart Knob". The "Smart Knob" will change the temperature of the stove by following the recipe. There are three critical phrases of synchronizing recipe on Smart Knob.

Let the user perceive the process of synchronizing recipe from phone to the smart knob.

Blink means the device is fully ready. Users can start at any time as they want.

Once the device is starting, The interface of the Smart Knob and the temperature of the stove will change to the specific setting responded to the recipe steps.

5. Physical twisting still on the first prioritize (offline status)

Users can stop the cooking programming or change the heating temperature by twisting the Smart Knob at any situations (disconnected status). It let users can fully control the device.


To delve deeply into practical situations while cooking, I put forward a Problems Scenario and highlighted some pain points users might have.


1. Unit Conversion
If users follow recipe while cooking, it is hard for them to transfer the temperature on recipes to the stove correctly.

2. Rental Apartment
An increasing number of young people are livining at rental apartment. They can not change the whole stove in a rental apartment. The product should be small and portable.

3. Chaos comes from multi-tasks
People used to handle a lot of tasks simultaneously while cooking, such as preparing the rest of the ingredients, adjusting heat temperature, keeping eyes on a timer, interaputed by your dog, etc. Completing all those tasks at the same time is not easy. That is where chaos comes.


To better define the design scope, I made a value proposition statement to narrow down the design context.



To make the value of product come true, three crucial parts are needed for creating main experience. Smart Knob- Device, mainly as an actuator; Interface of Smart Knob; Supporting App



The network behind the product is crucial to UX design. The system of IoT will exert a significant influence on how the user experience looks.
Instead of using the gateway as a bridge to connect a device with internet. I use WIFI Router as a bridge to embed Smart Knob to network. Here are two significant advantages to this choice:

1. Using Wifi as a gateway enable the Smart Knob to communicate with Google Home or Amazon Echo efficiently.

2. It makes the device more portable.

PROTOTYPE (Form Exploration)

I made a physical knob by using 3D print technology. And then I made a fake stove using foam core and combine it with a 3D printed knob and put the interface of knob under the artificial stove. This rapid prototype- fake stove- can draw people’s attention to the scenario and present this fantastic experience.

PROTOTYPE (Digital Part)

Design visual feedback for each status of experience.


A lot of middle statuses show up in the process of cooking. I utilized After Effect to design each animated interface..


I redesigned the supporting app after getting feedbacks from instructor and classmates. The redesign clarified the flow into three main flows (WIFI setup, chose and sync a recipe, follow the recipe).

Flow 1: Wifi Connection

Flow 2: chose and sync a recipe

Flow 3: following recipe step by step


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I recorded a video of doing the prototype testing. It'll show you how the final prototype works.


1. It is more beneficial to use foam core to build a low-fidelity prototype. It can quickly bring users your design scenario.

2. Generally speaking, the IoT system is more complicated than a single application implemented on a smartphone because the IoT system should be correspondent to reality, actuator, sensor, etc. Besides, different kinds of challenges are on the way, such as connecting Wifi will consume much power, and how do we solve it?

3. Speaking of IoT product, its network plays a vital role in the stage of design of UI and UX.

4. There are a potential and high risk of latency as well as an unsteady connection on IoT device. We have always think about the exit plans for "latency".