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A 4 V Operation,Flexible Braille Display Using Organic Transistors,Carbon Nanotube Actuators,and Organic Static Random‐Access Memory |
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| Authors: | Kenjiro Fukuda Tsuyoshi Sekitani Ute Zschieschang Hagen Klauk Kazunori Kuribara Tomoyuki Yokota Takushi Sugino Kinji Asaka Masaaki Ikeda Hirokazu Kuwabara Tatsuya Yamamoto Kazuo Takimiya Takanori Fukushima Takuzo Aida Makoto Takamiya Takayasu Sakurai Takao Someya |
| Affiliation: | 1. Department of Applied Physics, The University of Tokyo, 7‐3‐1 Hongo, Bunkyo‐ku, Tokyo 113‐8656, Japan;2. Department of Electrical and Electronic Engineering, The University of Tokyo, 7‐3‐1 Hongo, Bunkyo‐ku, Tokyo 113‐8656, Japan;3. Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569 Stuttgart, Germany;4. Research Institute for Cell Engineering, National Institute of Advanced Industrial Science and Technology (AIST), Midorigaoka 1‐8‐31, Ikeda, Osaka 563‐8577, Japan;5. Functional Chemicals R&D Laboratories, Nippon Kayaku Co., Ltd. 3‐26‐8, Shimo, Kita‐ku, Tokyo, 115‐8588, Japan;6. Department of Applied Chemistry, Hiroshima University, 1‐4‐1, Kagamiyama, Higashi‐Hiroshima, Hiroshima, 739‐8527, Japan;7. Functional Soft Matter Engineering Laboratory, Advanced Science Institute, RIKEN, 2‐1 Hirosawa,Wako, Saitama, 351‐0198, Japan;8. Department of Chemistry and Biotechnology, The University of Tokyo, 7‐3‐1, Hongo, Bunkyo‐ku, Tokyo, 113‐8656, Japan;9. VLSI Design & Education Center, The University of Tokyo, 4‐6‐1, Komaba, Meguro‐ku, Tokyo, 153‐8505, Japan;10. Institute of Industrial Science, The University of Tokyo, 4‐6‐1, Komaba, Meguro‐ku, Tokyo, 153‐8505, Japan;11. Institute for Nano Quantum Information Electronics, The University of Tokyo, 4‐6‐1, Komaba, Meguro‐ku, Tokyo, 153‐8505, Japan;12. Core Research for Evolutional Science and Technology, Sanban‐cho Bldg, 4F, 5, Sanban‐cho, Chiyoda‐ku, Tokyo, 102‐0075, Japan |
| Abstract: | A sheet‐type Braille display operating at 4 V has been successfully fabricated by integrating organic an static random‐access memory (SRAM) array with carbon nanotube (CNT)‐based actuators that are driven by organic thin‐film transistors (control‐TFTs). The on current of organic control‐TFTs that drive CNT actuators exceeds 3 mA, the mobility exceeds 1 cm2 V?1s?1, and the on/off ratio exceeds 105 at an operational voltage of 3 V. By adjusting the process time for the formation of the aluminum oxide dielectrics, the threshold voltage of the organic TFTs can be systematically controlled. This technique leads to an improved static noise margin of the SRAM and enables its stable operation with a short programming time of 2 ms at a programming voltage of 2 V. As a demonstration of the operation of one actuator with one control‐TFT and SRAM: the displacement of actuator exceeds 300 μm at an operation voltage of 4 V, which is large enough for a blind person to recognize the pop‐up of braille dots. Integrating the SRAM array reduces the frame rate of a 12 dot × 12 dot display from 1/21.6 s to 1/2.9 s. |
| Keywords: | organic transistors self‐assembled monolayers Braille display organic static random‐access memory |