First paper-based transistors
Portuguese researchers have created the first paper-based transistors. To be more precise, they've made the first field effect transistors (FET) with a paper interstrate layer. According to the research team, these new transistors offer the same level of performance as 'state-of-the-art oxide based thin film transistors (TFTs) produced on glass or crystalline silicon substrates.' Possible applications for these paper-based transistors include new disposable electronics devices, such as paper displays, smart labels, bio-applications or RFID tags. But read more...
You can see above the first paper interstrate thin film transistors developed by the Portuguese team. (Credit: CENIMAT) Here is a link to a larger version of this picture.
For those of you who want to know what's behind the acronyms mentioned in this post, here are two links to Wikipedia pages: TFT stands for thin film transistor and FET is short for field-effect transistor.
These transistors have been created at the Center of Materials Research ("CEntro de INvestigação em MATeriais" or CENIMAT at the Faculdade de Ciências e Tecnologia of the Universidade Nova de Lisboa (UNL), Portugal. The research team was led by Elvira Maria Fortunato, Associate Professor, and Rodrigo Martins, Professor at UNL.
The research team said that there is currently "an increased interest in the use of biopolymers for low-cost electronic applications. Since cellulose is the Earth's major biopolymer, some international teams have reported using paper as the physical support (substrate) of electronic devices. But, until now, no one had ever used paper as an interstrate component of a FET."
So how did the researchers used paper to build their new transistors? "The research team fabricated the devices on both sides of the paper sheet. This way, the paper acts simultaneously as the electric insulator and as the substrate. [...] Furthermore, electric characterization of devices showed that the hybrid FETs’ performance outpace those of amorphous silicon TFTs, and rival with the actual state of the art of oxide thin film transistors."
This research work is not currently available online, at least for you and me. It should be published in the September 2008 issue of IEEE Electron Device Letters under the title "High Performance Flexible Hybrid Field Effect Transistors based on Cellulose Fiber-Paper."
So we'll have to wait two months to discover more details about these findings.
Sources: AlphaGalileo, July 21, 2008; and various websites
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