Elastomeric Transistor with Softness and Robustness Comparable to Cloth
November 12, 2015 | AISTEstimated reading time: 4 minutes
Points
- The transistor is made only from elastomeric materials, such as single-walled carbon nanotubes, rubbers, and gel.
- The transistor can maintain its performance when stretched, bent, compressed, or struck, as every component deforms integrally.
- Potential applications are medical sensing systems and the skin of personal care robots.
Summary
Atsuko Sekiguchi (Senior Researcher) and Fumiaki Tanaka (former AIST Postdoctoral Researcher) of CNT Application Development Team, the CNT-Application Research Center (Director: Kenji Hata), the National Institute of Advanced Industrial Science and Technology (AIST; President: Ryoji Chubachi), have developed a transistor that shows softness and robustness comparable to cloth and will endure a wide range of loads (stretching, bending, twisting, compressing, and impact).
The transistor does not use hard materials such as metals and oxides, and is made only from soft carbon-based materials such as single-walled carbon nanotubes (SWCNTs), rubber, and gel; this allows all materials to be integrally deformed in response to the applied load. When the transistor is attached to a piece of clothing and worn, it will become a part of the fabric and fit the human body, causing little stress on the body. In future, it is expected to be applied to human-monitoring electronics in the medical field, such as biological sensing systems and the skin of personal care robots.
Social Background of Research
Electronic devices with softness comparable to cloth could realize the monitoring system of health status (e.g. pulse, presence or absence of arrhythmia, and skin temperature) in everyday life without causing too much stress on the human body. However, it has been difficult so far to realize a device that shows both softness and robustness, because conventional electronic devices are made from hard materials such as metal, oxide, and alloy.
History of Research
AIST has been focusing on the elastic properties of SWCNTs of network structure and has developed a conductive SWCNT rubber composite (AIST press release on October 12, 2011) and a SWCNT rubber composite with highly accurate moldability (AIST press release on August 28, 2013). In addition, because SWCNTs have metallic and semiconductor properties, AIST has also developed a technique for selectively separating out semiconductive SWCNTs that can function as transistors (AIST press release on May 11, 2011).
In the present study, the researchers utilized the electrical properties and elastic behavior of the SWCNTs of network structure in order to develop a transistor made only from elastomeric materials: they used the conductive SWCNT rubber composite as the electrodes and semiconductive SWCNTs as the channel.
Part of this study was supported by a research topic “Functional integrated CNT flexible nano MEMS devices fabricated by self-assembling processes” (Fy2009 - FY2013) included in the CREST research area Creation of Nanosystems with Novel Function through Process Integration of the Japan Science and Technology Agency.
Details of Research
The developed side gated transistor is schematically shown in Fig. 1 (top left). The source, drain, and gate electrodes are made from the conductive SWCNT rubber composite; the channel is semiconductive SWCNTs; the dielectric layer is an ion gel; and the substrate is silicone rubber. All constituent materials possess mechanical properties similar to cloth and no hard metal nor oxide was used. Characteristics of the transistor are shown Fig.1 (right). The on-current is –50 µA and the on/off ratio is 104, which are comparable to those of previously reported flexible transistors.
Figure 1: Schematic illustration of the transistor (top left), the constituent elements (bottom left), and its performance (right)
Page 1 of 2
Suggested Items
Real Time with... IPC APEX EXPO 2024: Sustainability in the Industry
04/26/2024 | Real Time with...IPC APEX EXPOGuest Editor Henry Crandall and Chris Nash of Indium Corporation discuss the company's 90th anniversary and its focus on sustainability. They focus on the benefits of sustainable materials, their compatibility, and value propositions. The conversation also highlights how Durafuse LT technology's role in reducing reflow temperatures is leading to significant cost and energy savings. Nash also touches on downstream sustainability efforts such as using recycled materials for packaging.
SMC Korea 2024 to Highlight Semiconductor Materials Trends and Innovations on Industry’s Path to $1 Trillion
04/24/2024 | SEMIWith Korea a major consumer of semiconductor materials and advanced materials a key driver of innovation on the industry’s path to $1 trillion, industry leaders and experts will gather at SMC (Strategic Materials Conference) Korea 2024 on May 29 at the Suwon Convention Center in Gyeonggi-do, South Korea to provide insights into the latest materials developments and trends. Registration is open.
Groundbreaking Ceremony Marks the Beginning of a New Era for Newccess Industrial; The Construction of the MINGXIN Building
04/12/2024 | Newccess IndustrialOn a clear and sunny day in March, the groundbreaking ceremony for the MINGXIN Building took place in Shenzhen, China. This moment marked the official commencement of construction for a project that will reshape the semiconductor materials industry.
The Need for a Holistic Global Sustainability Standard
04/10/2024 | Michael Ford, Aegis SoftwareNo one can deny that the resources of our fragile planet are finite. The environment seems like a third party, subject to constant degradation. We’re acutely aware of the effects of pollution on our climate, and despite our “throw-away” culture, recycling and recovery of materials has remained relatively expensive, even as we use more energy just to survive.
iNEMI Publishes Four Roadmap Topics
04/04/2024 | iNEMIThe International Electronics Manufacturing Initiative (iNEMI) announces the availability of the first roadmap topics in the new iNEMI Roadmap format. Printed circuit boards, sustainable electronics, smart manufacturing, and mmWave materials and test are now available online.