Journal #7 For Human living to a Hundred

 For relatively short period, the average life of human has been really increased. We can attributed this lengthened life to many factors like Medical, scientific knowledge, medications, general improvement of sanitation etc.

  Additionally, the mechanical energy harvester made by University of Arizona and University of Illinois, seems to contribute to this trend by allowing a medical device put on internal organs to generate energy by itself.

  Thin and flexible energy harvester is really innovative considering many restrictions of formal rigid energy harvester. Rigid, non-flexible harvester cannot be put into internal organs which move flexibly.

 This energy harvester is composed of two thin layers and piezoelectric elements between them. Piezoelectric elements harvest energy from small conformation change of internal organs when they are moving.

 According to the researchers, their ultimate goal is to free medical devices from batteries. As long as the devices are depending on the batteries for getting energy, there will be repeated surgeries for changing a battery with chances getting complication.

 I think it will need more time to realize this goal. For example, there need to be more experiment to ensure safety and efficiency in human body. Current experiment is most done with animals.

 However, when it is done, this will further length the human life in the future. As the researchers said, in the future, human can live with a whole artificial heart. Considering the development of devices and their impact on human life, it's really important to make the devices work properly without external supply of energy.

 When we get to the university of Illinois, I'd like to listen to Prof. Rogers about this experiment and talk about the future of these devices ; when we can use this kind of pacemakers, what effort we should put to make this amazing pacemaker into reality.


Read more at : http://uanews.org/story/tomorrow-s-pacemakers-batteries-not-included

Journal #7 Generating electricity from humidity (습한 환경에서 전기 생산하기)

 Though this technology isn't much related to our theme, piezoeletric energy harvesting, I was attracted to the title, 'Generating eletricity from humidity for I had been spending a whole week in rainy season. (My room is totally humid even right now..)

 MIT generate electricity from water droplets which are spontaneously jump away from superhydrophobic surfaces while they are condensed. In humid air there are lots of vapor and when the cool surface is prepared, they will change into water on that surface. And small droplets will gather to form a large one. According to MIT, during this process, the surface energy is converted into the mechanical energy. And the larger droplets spontaneously jump to the other plates and produce electricity because they have charge.

 On current lever, the output is quite good. Per square centimeter, it can produce 1 microwatt and when it is made into a size of normal camping cooler(50 square centimeter) it can charge cellphone in about 12 hours.

 For this process, the difference of temperature between device and air is needed. In short it needs humid air and cool surface. As this conditional restraint, it is expected to work in cave, river etc.

 According to the researchers who are working on this technique, this technique harvesting energy from condensation is novel idea and there has been no try to relate energy harvesting and condensation before.

Read more at: http://www.energyharvestingjournal.com/articles/generating-electricity-from-humidity-00006761.asp

 이번 여름은 유난히 덥고도 유난히 습한 것 같다. 오늘 아침, 간밤에 비가 내린 뒤 한창 방안이 습할 때 에너지 하베스팅 저널을 기웃거리다 정말 매력적인 제목의 글을 찾았다.
 '습기로부터 전기에너지를 만들기'

 MIT에서 굉장히 소수성인 표면으로부터 튀어오르는 물방울들을 이용해 전기 에너지를 만들어냈다. 주변의 습도 높은 공기에는 수분이 많이 함유되어있는데 이들이 찬 소수성 판에 닿으면 응결된다. 그리고 인접한 작은 물방울들이 표면장력을 줄이기 위해 모여서 큰 물방울을 형성한다. 이 과정에서 에너지를 갖게 된 큰 물방울들이 소수성 표면에서 튀어오르고 이때 다른 판으로 전하를 전달하며 전기가 생산된다.

 현재 기술로 생산량은 평방 cm당 1마이크로 와트 정도 이고, 50cm 평방 크기로 제작되면 12시간동안 핸드폰을 충전할 수 있다고 한다.

 이러한 전기 생산이 가능하려면 우선 주변 환경과 발전기 사이의 온도차가 필수적이다. 그래야 주변에 존재하는 수분이 응결될테니까. 따라서 동굴이나 강 주변에서 발전이 가능할 것으로 기대된다.

 연구원은 '응결이란 주제로 에너지 하베스팅을 구현한 연구가 기존에 없었다며 이번 연구는 굉장히 새로운 에너지 하베스팅 방법을 제안했다'라고 말했다.

Journal #6 High temperature piezoelectric materials

Journal #6 High temperature piezoelectric materials

 There are roughly 200 kinds of piezoelectric materials in the world. However, only a few of them are used to make products or researched. Because the piezoeletric materials have so many distinctive properties different from each other, like humans :)

 

 Today, in the article that I've read is a new face; High temperature piezoeletric materials made by Dr. Tim Comyn and Dr Tim Stevenson in Professor Bells Group. This material is unique in that it can be exposed to extreme environmental conditions such as high temperature or high pressure. And thanks to this property, the range of application is extended and also the potential market.

 

 The reason of its high stability in extreme environment is attributed to its components. There are some materials including bismuth and iron and these make the piezoeletric material tolerent to extreme external conditions.

 

 This development is said to be overcome the failure of current technology, according to Prof. Bell. The stronger the piezoeletric materials, the broader and utilizable the sensors using them. For example, people can check the internal condition of gas turbine or huge oil transfering tank with sensors made up of this strong piezoeletric material.

 

 What I'm interested in and wondering is the way this new material came out. Surely, the new compositions of piezoeletric materials are vigorously being developed by researchers. I'd like to know how they choose new elements or how they plan experiments.

 

 Through this article, I could realize there should be a good understanding of elements and their properties to do a research about piezoeletric materials. And this process is really important in making the piezoeletric technology be developed further in the future.

 

*Bismuth is a chemical element with symbol Bi and the atomic number is 83. It is classified into post transition metal and has poor mechnical strength.

 

Read more at: http://www.energyharvestingjournal.com/articles/high-temperature-piezoelectric-materials-00006267.asp

Journal #5 Compact vibration harvester power supply with highest efficiency

Journal #5 Compact vibration harvester power supply with highest efficiency
  The cooperation of OMRON and Holst Centre/imec gave a birth to a compact vibration harvester. It converts vibration into the electricity and is kind of a sensor. This harvester has some remarkable features; converting efficiency, size, output etc. 

 First, it converts and store energy in the microwatt range. Second, it has small size as 5 x 6 cm and could be reduced to 2 x 2 cm. Also it weighs only 15.4 gram. This compact size and weight make it possoble for the harvestor to be installed in various products and regions. Third, its output can be adapted to from 1.5 V to 5 V, which is the range enough to be used in small or low power wireless sensors.

 Currently the prototypes are installed through various fields to make a test result which appeal to potential customers. After gathering enough customers, the harvester will be made into large volumes.

 According to the article, there has long been a question regarding 'how can the sensor is autonomously powered?'. And it seems the answer is high efficient energy harvester. However, there are many problems to realize this answer. For example the vibration in the environment is not consistent and it makes hard to produce enough energy.

 I'd like to know further how this harvestor overcome this problem. I think if some problems are solved there will be numerous ways to use this kind of sensor. And it can be used to make human life more safer and better. For example in the nuclear power plant or overhead power line which should be checked for the safety.

 It seems we are almost near to realize this comfortable and safer sensor system in daily life.  
  

Read more at:http://www.energyharvestingjournal.com/articles/compact-vibration-harvester-power-supply-with-highest-efficiency-00006741.asp

Journal #4 Wireless train sensor harvests vibrational energy

Journal #4 Wireless train sensor harvests vibrational energy

 Seeing the articles updated in Energy Harvesting Journal, we can know the interest about 'sensor system' is increasing recently. Especially when it comes to the application of energy harvesting technique, sensor system is one of the most hot spot.

 In the journal is the wireless train sensor developed by Perpetuum and Southeastern Railways. As sensors, it is made to monitor the conditions of railways and trains. It collects the information of temperature and vibration and the information is sent for analysis. And thanks to the data, people can know the progression of the wear, detect the change and prevent the accident.

 However, the wireless train sensor is different with all other sensors in that it harvests energy and use this energy to operate itself. Perpetuum is first to introduce the system that is powered by energy harvested from vibration. According to the Perpetuum president, thanks to this system, rail asset life can be extended, operational function can be increased and safety can also be improved.

 Technology of vibration energy harvesting is the key technology of Perpetuum and they use the energy in brilliant way, to power the sensor system. Especially, the railway where there is abundant vibration, the effect of the technology will be increased.

 Though there is no specific mentions about the technology, the company might use the piezoelectric or triboeletric energy harvesting technique to harvest energy from vibration.

 As so many machines and techniques make human life convenient, there increases the need for monitoring the systems more carefully. I think the energy harvesting technique can be a solution for many other health and security monitoring in the future.

Read more at: http://www.energyharvestingjournal.com/articles/wireless-train-sensor-harvests-vibrational-energy-00006734.asp

Journal #3 "국내서 물방울 흐름 이용해 전기 만드는 기술개발" ("The power in a toilet flush")

Journal #3

"국내서 물방울 흐름 이용해 전기 만드는 기술개발"

서울대와 전자부품연구원이 전극을 넣은 뒤 전하 유도 필름을 붙이고 발수 코팅을 추가해 만든 전력변환 장치물방울 전지를 공동개발하였습니다. 물방울이 이 장치에 떨어지면 양전하와 음전하의 변동이 생기는데 물방울의 흐름을 통해 생긴 전기를 이끌어내는 방식입니다.

원문 기사 링크 : http://w3.sbs.co.kr/news/newsEndPage.do?news_id=N1002375294 (정영태 기자, SBS뉴스, 2014.05.05 )

"The power in a toilet flush"

Prof. Youn Sang Kim and his team at Seoul National University and Korea Electronics Technology Institute (KETI) have shown that only a few drops of water can generate power by converting the mechanical energy from water motion into electrical energy.
They reported their work in the Journal of Energy and Environmental Science in an article entitled “The Effective Energy Harvesting Method from Natural Water Motion Active Transducer.”

Read more at: http://www.washingtonpost.com/news/morning-mix/wp/2014/04/24/the-power-in-a-toilet-flush/  (Fred Barbash, The Washington Post, 2014.04.24)

Journal #2 'Kinetic-powered, web-enabled light switch'

Journal #2

'Kinetic-powered, web-enabled light switch'

White small switch attracts people's attention and they will be surprised by the weight of it. It doesn't have a battery because it can generate energy by itself. It use the kinetic energy generated by our finger tap to operate the switch. 

Philips brought out this new battery free switch on march 2014. According to Philips, people can use this switch when they can't use their smart device such as tablet, phone etc to operate Hue, personal wireless lighting system.  

I think this switch is distinguishable in that it is made at the point of fusion; the IoT concept and energy harvesting technique. In short, existing lighting based on IoT becomes more convenient with this wireless free battery switch. 

To sum up, this battery free switch shows the trend of piezoeletric or triboeletric energy harvesting technique. Many people working in this area say the best applicable area of these technique will be wireless sensor or switch. 

In addition, I personally felt that we can think of application of piezoeletric or triboeletric technique when we connect these to existing IT techniques like IoT. 


Read more at: http://www.energyharvestingjournal.com/articles/kinetic-powered-web-enabled-light-switch-00006706.asp

Journal #1 energy harvesting from jaw movement to power hearing aids

Journal #1

 'Energy harvesting from jaw movement to power hearing aids'

In this journal, we can know that the range of application of the piezoeletric technology is getting larger. Here is another application to hearing aids.

The key concept is this ; the invention gets energy from the ear canal dynamic motions to operate the hearing aids using flexible piezoeletric film. Through this film, the motion arising in the ear canal is converted into the energy. More specifically, the energy harvesting module produces energy from the motion caused by various ways such as jaw - joint activity.

Because there is a restriction of magnitude of energy produced by the technique, piezoeletronic energy harvesting technique inevitably has the unique area where it should be applied, the bio medical area.

I think it's quite interesting that the technique keeps finding the area where it could be applied like this example. Though it cannot make a huge amount of energy, the technique will improve many aspects regarding small but important medical devices in our daily life.

Read more at: http://www.energyharvestingjournal.com/articles/energy-harvesting-from-jaw-movement-to-power-hearing-aids-00006690.asp?sessionid=1