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Light Sensors Could Improve Medical Devices and Security Imaging

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Light Sensors Could Improve Medical Devices and Security Imaging

smartphoneThe implications of new and developing medical technologies in society today are vast.  Everyday new methods are discovered that will help us to track and monitor our health and wellness more effectively.  With the rising costs of insurance and the recent changes to the healthcare field many are looking for more affordable ways to maintain our health management. Here is an article about a particularly promising new development to medical devices that could have positive effects on healthcare.

Researchers at the University of Surrey have developed a new type of light sensor that could allow for medical and security imaging via low cost cameras.  Using these light sensors, near infrared light can be used to perform non-invasive medical procedures, such as measuring oxygen level in tissues and detecting tumors.  This technology is also already widely being used in security systems and for quality control in the food industry.

The new light sensor is able to detect the full spectrum of light, from ultra-violet (UV), to visible and near infrared light. It is the near infrared light that is most useful in this application. This new technology would allow surgeons to “see” inside tissues to find tumors prior to surgery and also be useful to consumer products such as cameras and mobile devices that could soon be equipped with night imaging options.  This is useful for capturing quality photos in the dark or allowing parents to monitor their child’s blood or tissue oxygenation level using only their Smartphone, which could then be linked to healthcare professionals.

[i]

The technology behind these new and exciting advances involves C60 Nanorods and Inorganic Photodoping[ii] and was developed by researchers at University of Surrey. One dimensional single-crystal nanorods of C60 possess unique optoelectric properties which makes them perfect for use in manufacturing low-cost large-area flexible photoconductor devices.  Researchers were able to enhance the photosensitivity of the C60 nanorods by using a very low photodoping mechanism. Photodoping is used to solve a naturally occurring problem.  When a C60 nanorod photoconductor device is irradiated with photons most of the excited electrons are concentrated in trap states rather than being available to contribute to the  photocurrent as a whole,  which reduces the responsivity and decreases the photosensitivity overall. To counteract this and to improve the photo-oxidation stability and extend the sensitivity of the device, researchers then introduced a photodopant. This fills the traps that naturally occur when C60 suffers degradation.  These photodopants must form a type-II heterojunction so that when the composite is photoexcited the photodopants provide the additional electrons needed to fill the C60 traps states. This encourages the photosensitivity needed to detect the full spectrum of light.

Typically when photodopant devices are introduced the donor to acceptor ratio is very high and the devices rely primarily on the absorption and conductivity of the donor material. In this case in order to achieve the photosensitivity required for the use of these light sensors in a medical setting, the photodopants introduced enhance the photosensitivity of the acceptor material (i.e. the C60 nanorods) and not the donor material.  To validate that the photodoped C60 nanorods truly experienced an enhancement of photosensitivity, the research team University of Surrey compared the responsivity spectrum of all the photodoped devices to that of an undoped C60 nanorod device.  When the tests were done and comparisons were read results showed that responsivity was increased in the photodoped devices by up to two orders of magnitude. This reinforced the idea that via an ultralow doping mechanism and careful selection of dopants and photodopants, both mobility and the photoconductivity of such a trap rich molecular organic semiconductor can be enhanced by many orders of magnitude.

While this technology may not be implemented and readily available to all within the next year, chances are that within the next decade these light sensors could be a standard part of all medical practices’.  This could conceivably greatly enhance preventative care and drive down costs of major procedures.  It also has major implications for security and military personnel as well.  It is appropriate to note that without the availability of semiconductor processing this technology would never have been plausible.

We hope that you found this overview of the article useful and interesting.  Please feel free to comment below and let the bloggers at Glew Engineering know if there is a specific topic you’d like us to blog about in the future.

 


[i] University of Surrey. (2014, May 23). New sensor could light the way forward in low-cost medical imaging. ScienceDaily. Retrieved May 23, 2014 from www.sciencedaily.com/releases/2014/05/140523082928.htm

[ii] Rinku Saran, Vlad Stolojan, Richard J. Curry. (23 May 2014). Ultrahigh Performance C60 Nanorod Large Area Flexible Photoconductor Devices via Ultralow Organic and Inorganic PhotodopingScientific Reports, 2014; 4 DOI: 10.1038/srep05041

 

By | 2016-12-15T22:25:23+00:00 May 4th, 2014|Mechanical Engineering, Semiconductor|0 Comments

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