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EDSGN 100 DESIGN

PROJECT #1

PROGRESS REPORT

TOOTHBRUSH DESIGN

INTRODUCTION TO ENGINEERING DESIGN

EDSGN 100 Sec. 25

Team #5

Siyang Liu sxl5507@psu.edu

Raymond Richlin rer5211@psu.edu

Nam Mi Suh Kim nos5310@psu.edu

Submitted to: Prof. Christopher Smith

Date: 10/20/2013

Executive Summary

Our team main objective and goal is based on creating a better electric toothbrush for kids

and teenagers. After gathering and analyzing the customer needs, a new design was made by

changing its outside appearance to make it look more attractive as well as manipulating some

features to satisfy customer and the company’s needs. Also, a change in the position of the

switch and the power transmission inside the device was made. As the result of our design,

the body part became smoother and smaller. The new switch is smaller and unified with the

body better. Our new design will have less energy loss, which means the toothbrush will

work longer and more efficiently compared with the original one and it has a bigger potential

to earn higher profits and revenues than the old toothbrush model.

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Toothbrush Design Project

Table of contents

Contents 1.0 Introduction ....................................................................................................................................... 3

1.1 Initial Problem Statement.............................................................................................................. 3

2.0 Customer Needs Assessment ............................................................................................................ 3

2.1 Hierarchy of Customer Needs ....................................................................................................... 4

2.2 Revised Problem Statement .......................................................................................................... 5

3.0 External Search ................................................................................................................................. 5

3.1 Literature Review .......................................................................................................................... 5

3.2 Benchmarking ............................................................................................................................... 5

3.3 Design Target ................................................................................................................................ 7

4.0 Internal Search .................................................................................................................................. 7

4.1 Concept Generation ...................................................................................................................... 7

4.2 Concept Selection ....................................................................................................................... 11

4.3 Prototyping and Design Reviews ................................................................................................ 11

5.0 Final Design ..................................................................................................................................... 11

5.1 Parts List of the Final Design ...................................................................................................... 13

5.2 Instructions for Assembly ........................................................................................................... 13

5.3 How it Works? ............................................................................................................................ 13

6.0 Conclusion ...................................................................................................................................... 14

References ............................................................................................................................................. 15

Appendix A – Survey sample ............................................................................................................... 16

Appendix B – Face to Face Interview Sample ...................................................................................... 16

Appendix C – Pugh Chart ..................................................................................................................... 16

Appendix D – Final Design of Toothbrush: Assembly of Parts ........................................................... 17

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1.0 Introduction Our team was assigned the task of creating a better design for an electric toothbrush in a

limited amount of time. There are four members in our team, and each of us was assigned a

certain part or section of the entire work. A screwdriver was used to open the original

toothbrush and be able to take out its batteries. A balance, an ampere meter and a voltmeter

were used to analyse the external and the inside “electric” structures. Also, photos were taken

of each part we dissected. Next, sections from 1.1 to 2.2 analyse the customer needs. Patent

research and benchmarking will be described in section 3.0 to 3.3. Then, the concept

generation and concept will be presented in sections 4.0 to 4.3. Finally the final design related

information and conclusion is presented on sections 5.0 to 5.3 and 6.0 respectively, at the end

of the report, and at the very last of the report the appendix will be available.

1.1 Initial Problem Statement

Design a toothbrush that is handheld, battery powered, and safe for ordinary daily use. It

should be water resistant, as well as having the main function of cleaning the teeth

thoroughly. It is designed for kids or teenagers between the ages 7-12 years old.

2.0 Customer Needs Assessment

After issuing the problem statement, we gathered the actual customer needs to maximize

the selling potential of our product and satisfy the customers. It is necessary and very

important to set our design target so that we can enlarge our profits and revenues. By doing

so, we sent out a total of 96 surveys and performed face-to-face interviews with a random

group of people, in this case college students. We selected these two methods because they

are considered inexpensive, accomplished in a relatively short period of time and have a very

small cost per participant, in terms of time invested in completing both the survey and the

interview. Surveys are very useful in describing a general tendency for the characteristics of a

large population. Also, the face-to-face interviews can increase the amount of information

obtained, meaning the response is not limited to just filling out some questions, but there

exists a better interaction between the person interviewed and the person doing the interview;

more specific questions can be asked and therefore the person interviewed is able to express

better his or her thoughts than rather writing it on paper. In the short time and low budget

conditions, we considered these the best ways to gather customer needs.

Survey/ interview participants: male and female Penn State college students, age from

18 to 22, randomly selected, including students from a wide variety of cultures and

ethnicities.

For the first step to gather the customer needs each team member asked people in their

surroundings what he or she thought might be the biggest concerns when choosing an electric

toothbrush. After that process, all responses were recorded and summarized. A survey was

also made and distributed to a group of random people at the University Park campus, State

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College, Pennsylvania. The survey was anonymous and the participants were told to rank the

options according to their opinions. The final result shows male participants had more interest

on the performance and less on appearance than female participants when choosing an

electric toothbrush.

*Survey sample and the interview script with the questions can be found in the Appendix A

and B respectively.

Table 1 — Customer needs survey feedback

Importance

Customer needs 1 2 3 4 5 6

Softness 22 17 17 12 1 3

Cost 21 17 16 6 5 5

Apperance 19 13 10 11 8 9

Noise 5 11 9 12 19 16

Brush Size 2 11 13 15 16 13

Weight 2 4 6 16 17 26

2.1 Hierarchy of Customer Needs

After the conclusions were made from the results of the surveys and the interviews, a

hierarchy of customer needs was developed. It is crucial to take this step in the design process

because it ranks the most important customer needs in an organized manner; these become

specific areas in which the team needs to focus on to develop a product that will attract and

satisfy the customers as well as generate and maximize revenues and profits for the company

when it is finally launched in the market. Each category was ranked from the most important

characteristic to the least important one, according to the results obtained from the

participants’ surveys and interviews. As seen below, the final results shows customers

consider the softness of the brush, the cost and the appearance the three most important

characteristics when choosing an electric toothbrush.

Table 2 — Hierarchy of Customer Needs

Category Rank

Softness 1

Cost 2

Appearance 3

Noise level 4

Brush size 5

Weight 5

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2.2 Revised Problem Statement

We will consider a fixed tooth brush head and an easy assembly of body parts to ensure

low costs of production and additionally a more organized appearance for the product. The

appearance is a major feature for our design, as mentioned earlier, our target market will

include young children and teenagers so in order to attract this target market the design must

look attractive in terms of colours, any animation or cartoon figures used. Light but resistant

plastic will be used for the different types of pieces, and the inside moor will be powered by

AAA batteries. Due to the fact that the main users of this product are children, batteries and

any kind of detachable parts, such as, the battery cap, must be secured to avoid any further

injuries to the child or damages o the product itself. The design of the toothbrush will be

handheld and water resistant and finally it will perform its cleaning task through vibrating or

rotational type of brush.

3.0 External Search

Performing an external search is an essential part for a product design and development

process. Through this methodology, the team is able to explore the current market regarding

the product that will be designed. Our team gathered information about the electric

toothbrushes and our specific toothbrush through the internet and compare and contrast data

about other teams’ toothbrushes. This helps to get a better idea of what types of products are

already in the market, selling to the consumers and therefore guide us to be able to develop a

better, more efficient and improved product.

3.1 Literature Review

The object our team has selected is the Spinbrush Kids Marvel Collection: Captain

America electric toothbrush. The price of this toothbrush ranges from $7.00 to $13.00 in

several online shopping websites, such as, Amazon and Ebay. The Spinbrush Kid’s Battery-

Powered toothbrush designed its products with smaller heads which are directed to its target

market: the children population. It includes two replaceable AAA batteries and has great

handle designs that would attract children and make brushing fun. Permission was awarded to

the company from Marvel Characters B.V. to allow the usage of its characters as part of the

external, physical design of the product.

3.2 Benchmarking

In this section similar products were compared in order to analyse the different types of

electric toothbrushes available in the current market. For this project we decided to perform

the benchmarking with other teams from our Engineering Design 100 class. Two other teams’

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toothbrushes were compared; Team 1 and Team 3’s toothbrushes, Sonicare and Oral B Pulsar

respectively were compared to our product, the Spinbrush Kids electric toothbrush.

Table 3 — Benchmarking of Three Types of Electric Toothbrushes: Sonicare, Oral-B

and Spinbrush Kids

Feature Team 1

Sonicare

Team 3

Oral-B PULSAR

Team 5

Spinbrush Kids

Packaging Easily opened, all

pieces well organized

and displayed

Pre etched

cardboard in the

back makes it easier

to open

Flashy front cover made of transparent

plastic; multilingual instructions on the

back side; Marvel’s Captain America figure

on the package

Aesthetics Use of simple colors,

such as, blue and

white

White marine and

light blue base with

a yellow, white and

blue brush.

Very colorful design including “The

Avengers: Captain America” figure on the

package and toothbrush

Handle

(Ergonomics)

Sleek and manageable

in size, easily held

Firm rubber grip,

comfortably adapted

to the user’s hand

Awkwardly shaped due to the big button

with Captain’s America’s shield form,

handle too big for a child, made of plastic

only

Weight with

batteries

Very lightweight 0.8 g 83.8 g

Safety No sharp ends that can

hurt the user; batteries

and other pieces

secured safely inside

Very safe to use, no

sharp parts, no

external moving

parts.

Children under 3 should use under an

adult’s supervision; do not submerge in

water as the unit can be damaged

Quality Average Overall good

quality, rigid

material

Overall good quality, made of hard plastic

material

Ease and

convenience of

switch use

Requires a certain

amount of force to

turn the power on/ off.

Simple and easy to

use

Switch is too big and it makes it

uncomfortable because it bumps with the

hand during its usage, awkwardly holding

of the toothbrush handle

Average noise

level (db)

15.65 db 70.9 db

Type of

batteries

required

AA type batteries 1 AAA battery 2 replaceable AAA

Additional/

Other features

Flossing attachment

Gum stimulator

Sulcus tip

One battery cycle,

not replaceable.

Massages gums

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3.3 Design Target

Through the external search many points of comparison were established between the three

toothbrush brands: Sonicare, Oral-B and Spinbrush. The main difference can be determined

regarding the target market; Team 1 and Team 3’s toothbrushes from Sonicare and Oral-B

respectively are targeted to teenagers and adults, whereas Spinbrush’s toothbrush, in this

particular case, is directed to the children population. Features, like the gum stimulator and

the flossing attachment might be convenient for an adult’s toothbrush design, but for the

younger children, a simple, easy to use, light and attractive toothbrush is much more

convenient as children are not yet able to perform several cleaning tasks by themselves. Our

team’s design targets will be focused according to the customer needs hierarchy: the softness,

the cost, the appearance as the three most important and therefore will have a greater

“weight” when designing the toothbrush. The noise level, the brush size and the weight will

also be considered for the design but no as much as the first three customer needs.

4.0 Internal Search

Internal search is a kind of studying of our original design. We conduct this task by

opening the product and measure every its property data.

4.1 Concept Generation

For the concept generation process we decided to use the brainstorming method. All

members came up with different ideas as well as sketches not for specific customer needs, but

for whole toothbrush designs involving several customer needs at once; after the ideas came

up we all gathered the information and details to come up with some designs that would lead

us choose our final one. As seen below, in Table 5, the morphological chart shows all the

different designs our team came up with. One concept that changed in every design was the

movement or design of the brush head, the same from which the toothbrushes got their

“names” or “identities” and therefore this would influence on how the motor inside the

toothbrush would perform its task. There are 5 designs resulting from the brainstorming: A.

Rotation, B. Up and down, C. Sliding, D. Vibration, and E. Top Spin. Some of the most

unique ideas resulting from our concept generation were from the Up and down design and

the Top spin design; in the first one the size of the brush head and brush as well would be

relatively big and the brush head entirely would go up and down, as seen in the figure below.

For the top spin design it is even more “special”; it imitates the external form and appearance

of a wand, having the brush head directed upwards, and the user would have to grab it in a

way that the brush head would end up perpendicular to the teeth to be able to clean the teeth.

Below is the morphological chart as well as the dissection of our original given toothbrush,

the Spinbrush Kids Marvel’s Captain America’s toothbrush.

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Table 4—Morphological chart

Toothbrush design Functions

A. Rotation

Brush (only bristles) rotates through the use

of two gears.

It is easy to use as the child needs to hold the

toothbrush like any other one and the

“bristles” will do their work.

Use of same plastic material as the original

design.

B. Up and down

The entire brush head goes up and down.

The brush head is big in size.

A rubber piece helps the motion of up and

down go smoothly.

Use of same plastic material as the original

design.

C. Sliding

Only the bristle part “slides” up and down.

This is achieved by the motor inside the

toothbrush.

Use of same plastic material as the original

design.

D. Vibration

Brush heads vibrates in same position.

There is a motor just behind the bristle part

that makes the bristle and the brush head

vibrate in place.

Use of same plastic material as the original

design.

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E. Top Spin

Also called the “wand” toothbrush, it

performs its task by holding the toothbrush as

well as the brush head (bristles) perpendicular

to the mouth and teeth. As shown in the figure

at the left, the toothbrush is located facing

upwards rather than to the right as a “normal”

toothbrush would.

The brush head rotates 360 degrees every

time it spins.

Needs several small pieces to achieve this

motion of 360 degrees.

Use of same plastic material as the original

design.

Original Spinbrush Kids Design

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Labels:

1. Outer plastic cover of the toothbrush (with Captain America’s figure on it)

2. Switch on/ off button (Captain America’s shield design)

3. Brush head with bristles

4. Battery cap (made of plastic and screwdriver needed to take out the batteries)

5. 2 AAA replaceable batteries

6. Internal pieces of the toothbrush; this includes motor, gear, etc.

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4.2 Concept Selection

The next step towards our final design is the concept selection. Through the concept

selection, concepts are chosen in order to come up with the final design of the product.

Through the concept selection process the team chooses the most important concepts that

satisfy both consumer needs and the company’s needs and ranks them in order to come up

with a final idea of how the new product’s design and functions should be.

For this design project the Pugh Chart method was used. A reference concept should be

chosen in order to be able to compare it with the other designs. In this case we selected the

original Spinbrush Kids design as our reference concept and instead of introducing specific

concepts we decided to come up with several different toothbrush designs and compare and

contrast them making reference to the selection criteria. The Pugh Chart method is a very

useful for this step as the different concepts or designs can be ranked according to the

selection criteria; the ranking is achieved by providing a relative score to the design for each

criteria. The toothbrush’s bristles softness will come in two different levels: soft and medium

softness as children’s teeth are still very sensitive and “weak”.

* Pugh Chart is shown in Appendix C

4.3 Prototyping and Design Reviews

The idea we prototyped was the sliding plate method of the inside workings of the

toothbrush. We only prototyped one of our ideas because we were able to screen which ideas

was not going work. The prototype is the same design that used for our final design of the

toothbrush.

5.0 Final Design

The final design is a toothbrush with a face separate from the brush head that oscillates up

and down through the use of a battery powered motor and gears.

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*See appendix D for link to detailed sketch of solid works assembly

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5.1 Parts List of the Final Design

Table 5-List of parts of the final toothbrush design

5.2 Instructions for Assembly

To operate the toothbrush, press the button on the front of the toothbrush once to turn it on.

To turn the toothbrush off, press the button again. To remove the batteries, press in the sides

of the battery compartment and pull out. To put the batteries back in, push the battery

compartment back in until it clicks in place.

5.3 How it Works?

The toothbrush works by using a dc motor connected directly to a small gear to turn one

other gear. This gear moves a rod up and down that is connected to a plate on the head of the

toothbrush.

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6.0 Conclusion Our project was successful in that we designed a new mechanical toothbrush that meets the

needs of the customer. It is simply designed, making it cost less to produce which in turn

would allow it to be sold for a cheaper price. It is easy to handle and is designed to be

ergonomic. The mechanical aspect of the brush is truly unique because it was made from the

heads of our own team and does not exist in any other brush.

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References Amazon.com http://www.amazon.com/Spinbrush-Battery-Powered-Toothbrush-

captain/dp/B007ABCM4E

Ebay.com http://www.ebay.com/itm/NWT-KIDS-SPINBRUSH-CAPTAIN-AMERICA-

MARVEL-HEROES-AAA-BATTERY-OPERATED-TOOTHBRUSH-/271203216232

Spinbrush http://www.spinbrush.com/kids.html

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Appendix A – Survey sample

Rank the qualities in the order of importance for an electric toothbrush.

(1-most important, 6-least important)

Category Rank

Softness

Cost

Appearance

Noise level

Brush size

Weight

Appendix B – Face to Face Interview Sample

What do you think is important for you to choose a electric toothbrush?

What do you think is important for a kid to choose a electric toothbrush?

Do you care more about its performance or cost?

What price do you think is appropriate for you?

How often you change your electric toothbrush?

Appendix C – Pugh Chart Toothbrush designs

Selection criteria

A

Rotation

B

Up and down

C

Sliding

D

Vibration

E

Top spin

F

Original Spinbrush

Kids design

Ease of use

Durability

Cost

Ease of manufacture

+

0

0

-

-

0

-

-

+

0

-

-

+

0

-

-

0

0

-

-

0

0

0

0

Sum +’s

Sum 0’s

Sum –’s

1

2

1

0

1

3

1

1

2

1

1

2

0

2

2

0

4

0

Net Score

Rank

0

0

-3

4

-1

2

-1

2

-2

3

0

Reference concept=0

*Relative Score: Better than (+)

Same as (0)

Worse than (-)

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Appendix D – Final Design of Toothbrush: Assembly of Parts

** (required Solidworks program to open file)