Interactive Design & Physical computing   |   Individual work   |   2018 Summer

I would like to add entertaining elements to the stone-heavy schoolbag. By endowing it with music or a special touch , I hope to turn it into an interactive,  ironic multi-media bag, behind the appearance of a hard, cold stone.

Design description


The inspiration comes from a craft project of mine several years ago. At that time I was carrying a heavy schoolbag every day, as heavy as a big stone. So I came up with the idea of designing schoolbags into the shape of a stone, which also symbolizes the academic and job-search stress  faced by college students. Moreover, while transporting the “stone” day after day, students improve their overall capacity and finally grow into outstanding professionals.​​



"I'm light" and other entertaining words will be displayed with Ardurino package installed on the stone-patterned backpack.

There is a pedometer and an automatic weigh-in on the backpack, which will count the weight of the backpack and how far the users walk with it every day, and give rewards when they reach a certain degree.


Work Reference

Mind Map


Design Proposal

Meiosis backpack is an equipment bag.The tension and flexibility of the design maintains its shape while it is opened and closed.

There is an independent LED light in each block plane. And the backpack has a Bluetooth module, according to the rhythm and volume of music, to control the flashing of LED lights. 

I was carrying a heavy schoolbag every day, as heavy as a big stone. So I came up with the idea of designing schoolbags into the shape of a stone.

The Bluetooth module can only recieve music from a speaker, so if a Bluetooth module is needed, the surroundings need to be taken into account when using it, so the scene is limited.

A set of air pumps control all the airbags, inflating them during the day and contracting them at night. When the students are outside, the backpack is inflated. And the airbags shrink when in the desk.

Each independent airbag has a LED light. When pressing it, the air pressure inside the airbag will change, so as to trigger the LED light and customed soundtrack.

The air pump has 2 ports and can only be used for air inflation or exhaust. Therefore, a backpack will need many air pumps.

The air pump has 2 ports and can only be used for air inflation or exhaust. Therefore, a backpack will need many air pumps.

After inflating, the airbag lacks edges and corners, and the original stone shape will be expanded, losing its stone features.

As an airbag requires two air pumps, so the airbag scheme is abandoned and I change trigger into the pressure sensor or switch.

Target users:

College students who need to carry the heavy schoolbag with them over 2 or 3 hours per day. 

Design methods:

It is an entertaining schoolbag, looking like a stone with multiple sides. Each side  is inserted with an  LED bulb and the whole bag with a speaker, through which funny sounds set on the app are played. The entertaining design  increases interaction between students through their schoolbags and hence relieves them of their fear and anxiety about schoolwork.​​


Problem Research

Pressure sensor or switch?

The difficulty of interaction is divided into three parts according to the trigger function and tactility. 

To reach the best tactility

Different lighting modes 

Choose manner of articulation

Will the color change?

Soft surface or hard surface?

How long does the lighting last? Will it go out when hands move away? 

Pressing surfaces to play different music or sounds is interesting.

Flash or not?

Do users use regular or custom music or sounds? Do users load music by the App via Bluetooth?

Is there only one Speaker in the backpack

or multiple Speakers? When pressing, the

Speaker will be triggered.

Material Experiment 


Choosing LED lighting


Ways to load music

Choosing of music

Speaker Decision:

As a whole, the backpack uses only one Speaker. Every time when each plane is pressed, the digital signal will be transmitted to the Arduino mainboard, and the Speaker will be controlled by the Arduino, saving digital resources.

Micro SD

Use the MP3 module to play the music in Micro SD card

Dia. 20mm, brightness 6000+ cmd, operating voltage 5V

RGB LED 5050

LED 5050 Module

Dia. 40mm, operating voltage 12V

LED Decision:

RGB led module, it integrates four LED lamp beads, which is much brighter than the other two LED components, and saves the Arduino port to the greatest extent.

RGB LED Monome

Load mode Decision:

Dia. 5mm, brightness 1000 - 5000 cmd, operating current 15-20mA

Through the App of the product, users can select the sound the Speakers will play when the block plane of backpack is pressed. A selection of sounds on the App contains a variety of styles, which meets users’ needs in different scenarios, and will be updated on a per-issue basis.


APP control the speaker through Bluetooth to play the music


Users could upload their favorite mudic or sound

Choosing of Speakers

Light Decision:

Music Decision:

Funny Sound

Users can choose from several pre-defined music modes, or customize the music.

When pressed, the backpack would play funny sound

Music genre

Different planes play different genre of music

How long does it last?

The device, flashing LED lights, is designed to make the backpack lively, and users may customize very funny sounds or music. Besides, the flashing LED lights are more lively than the constant lights.


Ways to trigger

3\  Decision

1/  Switch

The acrylic board is supported by 2 switches, and the plane of button is glued to the acrylic board to make it fixed and stable. The switch can be triggered when pressing anywhere, therefore the experiment is successful.

2\  Pressure sensor

This pressure sensor is too small compared to the acrylic board, so if pressing the edge part of the acrylic board, the pressure sensor can not sense the value.

Since this experiment only requires triggering, and does not need to adjust the backpack response according to the pressure value, so Switch is the best scheme, which can trigger accurately as well as meeting the experimental requirements.

The toner is ground into granules to simulate the graininess and roughness of the stone.

Tactility and material experiment

Silica gel & Toner

Making process

Silica gel & Oil-based pigment

I wants  the surface to resemble that of a stone, yet to be a little bit elastic when being pressed. This makes pressing and poking more fun and encourages users to interact with each other.

6/ Put together the silica gel 
and carylic panel

The silica gel with different shades of color is made to reflect the shades of the stone.

Silica gel

Transparent silica gel could not represent stone texture

1/ Grind the toner

2/ Add the toner powder and pigment into te silica gel

3/ Solidification

4/ Shape the silica gel

8/ Various levels or patterns 
of gray shading 

7/ Light test

5/ Choose 3mm white 
frosted acrylic panel


Circuit Making

Material list


Test. When the button is pressed, the Speaker would play the music.

Attach LED module to Arduino. The positive pole of LED connect to the Relay. When the Switch is pressed, LED flash.

Save the music in SD card, when the pin on MP3 Module is triggered, it would play music.

Connect Speaker to the circuit.



Prototype Making and Test

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