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Infrared Detection of Elevations in Mobile Phone Temperatures induced by Casings
* 1, 2 , 1 , 3 , 4
1  Applied Renewable and Sustainable Energy Research Group Department of Mechanical Engineering University of Nigeria, Nsukka 410001, Nigeria.
2  Department of Mechanical Engineering Science Faculty of Engineering and the Built Environment University of Johannesburg, South Africa.
3  Department of Mechanical Engineering University of Port Harcourt, Choba, Nigeria.
4  Department of Mechanical Engineering University of Nigeria, Nsukka 410001, Nigeria.


The design and usage capacity of mobile handheld devices have advanced tremendous in recent times, from being used solely for audio calls to the recent incorporation of augmented reality in smartphones. These new smartphone applications are power intensive causing excessive heating in phone parts, primarily batteries and processors. In some cases, the temperatures of phones in use exceed the 45 C threshold temperature of discomfort. These undesirable high temperatures affect user experience and form the basis of ongoing studies to improve thermal management in handheld devices. This work analyzes the thermal profiles of three smartphone models A, B and C for common tasks such as music playing, voice calling, video streaming and 3D online gaming. Transient surface temperature distributions were obtained with infrared imaging and thermocouple sensors, while processor and battery temperatures were obtained from inbuilt sensors, for the phones operating with and without phone casings (test and control cases, respectively). Test results showed that casings generally inhibit the dissipation of the heat generated within the phone, leading to increased processor temperatures. Comparisons between thermal profiles for different phone casing materials showed that plastic casings caused the least temperature difference throughout the test duration, followed by silicone, carbon fibre and leather casings, in ascending order. The rises in processor temperatures during the test duration were compared for the different smartphones: the phone B had the least temperature rise, followed by phone A and then phone C. These gave indications of the power consumption by the phone processors when undertaking the test tasks.

Keywords: infrared sensing; thermal management; mobile phones; electronic packaging
Comments on this paper
David Okafor
Great article.
Many people cannot live without their smartphones. This research will help in ensuring better use of the devices.
Howard NJOKU
Thanks David for your positive assessment of our work.

Nmesoma Idika-Kalu
Very very nice. Well done man.
Howard NJOKU
Thanks Nmesoma. Happy that our work was well received by you.

Akay Udeh
Wonderful research
This is a very interesting read. I applaud those that carried out the research.

I think the plastic casing's advantages out weighs its disadvantages because these days, most smartphone uses hardly make or take audio calls and even when they do, it's usually with a headset or earpiece thereby reducing contact with the skin and avoiding the discomfort it comes with.

The casings that incorporate phase change materials are a really good idea but have casings like that been made or found their way into the market?
Howard NJOKU
Hi Akay.

Applause is humbly received. Your comments are also well received on the fact that with the use of ear phones, the skin heating effects of phone casings are avoided. However this doesn't mitigate the deleterious effects of the heating on the internal components of the phones.
Howard NJOKU
Furthermore, whereas casings with PCMs have been attempted in research investigation, I'm not aware of their commercial implementation as yet.

Tochukwu Nwokolo
Good one! Should we do away with phone casings altogether?
Howard NJOKU
Thanks Tochukwu.

We shouldn't do away with phone covers, but be aware of the implications of their use on phone performances.

Nasa Nilla
Good one!
Very insightful and relevant paper.
Howard NJOKU
Thanks Nasa.

Okeke Micah
A very necessary research. One really has to have the temperature profile of their smartphone Great paper!!!!!
Howard NJOKU
Thanks Okeke.
Howard NJOKU
Thanks Okeke.

Osinachi Benjamin-Ani
Phones and Skin
Any device at the threshold temperature of our bodies, no matter how useful, becomes a menace. As our dependence on this handheld devices increases we need to totally understand and control their effects on us. Kudos team, for this work.
Howard NJOKU
Thanks Osinachi. Perfectly agree with you.

Obatobi Ayeni
A very informative article... I remember when Razer made the arctech case in an attempt to solve this problem for mobile gamers. Nice one.
Howard NJOKU
Thanks Obatobi.

Tobechukwu Eneh
Health implications
Beyond the feeling of pain and heat felt on the contact of the display surface on the skin during voice calls, had there been any other research into the possible carcinogenic effects of the radioactive waves emitted from the device...
Howard NJOKU
Hi Tobechukwu. I'm aware that such studies exist, but this is outside the scope of the present study. None of those studies has shown definitive proof of any links between phone usage and the pathological conditions mentioned.

Aroh Valentine
The future
I'm really impressed by this piece. I just wish the results and conclusions would be looked into because of the possibilities of skin malignancies or any other which may arise as a result of these.
Howard NJOKU
Thanks Aroh.

Ifeanyi Kalu
This work is relevant for the time.

Chikere Chiedozie
Beautiful work
Nice work....I'm now aware of the effects of d various phone casings on phone performance. Speaking of d suggestion of using phone covers with PCMs incorporated in them is a nice solution.

Omeje Emmanuel
Nice Work.
It's really insightful. It would also be good to point out the effect of radiation from phones to human most especially men that keeps their phones in the trouser pocket.

I want to ask which of the above mentioned phone casings is best for usage?
Howard NJOKU
Hi Emmanuel,

Our findings suggest plastic casings.

Chidum Ezegwui
Good read.
As smartphones are here to stay and can give rise to health complications that weren't faced before, it's great certain effects that rise due to usage are brought to light.

To ask, are plastic covers recommended above other types of covers?
Howard NJOKU
Hi Chidum,

The findings of the full study suggest this.

Chibueze Nnaji
Nnaji Chibueze
This is a very nice article.

I actually learnt something from this. I never new phone casing contributes in phone's heating.

Also it will help one in choosing the type of phone case to purchase..

Please Sir can you advice us on the type of phone casing to buy that its optimal for both heat and radiation?.
Howard NJOKU
Hi Chibueze,

Our findings suggest plastic casings.

Ozioma Omeke
Excellent work! This research work will go a long way in prolonging the life span of mobile devices through enhanced thermal conditions.

Felix Asuquo
Great research work.

Very expository and informative on thermal radiation from handheld devices and the choice of material for phone casing.

Emmanuel Agbo
Good read.
This is a very interesting topic as most manufacturers of phone cases use hard plastic materials which protects the smartphone but is a poor conductor of heat. This work is very relevant in today's world. Kudos to the team.
Howard NJOKU
Thanks Emmanuel.

Chu Ngwoke
Well done!
A very necessary research. I’ve had good experiences with leather casings.
Kudos to all the researchers involved.

Uwazuruike Uchenna
Wow!!! This is a wonderful article Sir.More power to your elbow.
Wow!!! This is a wonderful article Sir.More power to your elbow.

Sir I will also suggest if you can also lay more emphasis on Radiation.
Howard NJOKU
OK. Thanks Uchenna.

Chukwumaobi Oluah
Well done!
This is research work is quite innovative and commendable.

Great work sir!

Onyinye Ikejiofor
An insightful research!!
Now I understand why my phone's temperature goes down whenever I take off the casing off.... A good one indeed.

Chioma NJOKU
Very Relevant Study
Are there currently phone casings with these phase changing materials for use?
If not, that's an area manufacturers need to look into to improve mobile phone user experience.

Very relevant research, kudos!

I'll be careful to use my earpiece or speaker more to keep the heat from being redirected to my face.
Howard NJOKU

I'm not aware of any casings in the market that incorporate PCMs. It would be good that commercial prototypes are attempted.

Miracle Mbaekwe
Pertinent study, Applause!
I commend the team for coming up with this interesting and relevant research. It is of no doubt that phone casing improves user experience and comes sometimes with the added advantage of aesthetic allure. Therefore, I want to see the possibility of retaining the use of phone casing and yet cutting down drastically on the internal heat accumulation, atleast, somewhere similar to that of phone without casing. This can be achieved with better design consideration of the casing. A glance at the thermograms show primary heating zones of the smartphones on different applications. Casing designs can be adapted such that these zones are allowed access to convective air flow for better cooling.
Kudos again to the team!
Howard NJOKU
Hi Miracle,

I agree with you. There could be designs with openings next to the locations that experience over heating. This will also be a cheaper solution than the incorporation of PCMs.

Thanks for the new insight.

Uchechukwu Njoku
Informative paper
Great paper.
I hope the industry takes this on to consideration and standardise it. Thanks for enlightening us, so we look into the materials of phone casting before purchase

Augustine Nwafuru
My Comment
Absolutely great work. A good read.