Thermally stable, adhesively strong graphene/polyimide films for inkjet printing ultrasound sensors. (30th October 2021)

• Record Type: Journal Article
• Authors: Zhou, Pengyu; Liao, Yaozhong; Yang, Xiongbin; Su, Yiyin; Yang, Jianwei; Xu, Lei; Wang, Kai; Zeng, Zhihui; Zhou, Li-min; Zhang, Zhong; Su, Zhongqing
• Is Part Of: Carbon. Volume 184(2021)
• Page Start: 64
• Page End: 71
• Publication Date: 2021-10-30
• Subjects: Inkjet-printed sensor -- Liquid exfoliation -- Graphene -- Polyimide -- High frequency ultrasound; Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2021.08.007
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: Targeting for flexible, broadband ultrasound sensors, a new breed of nanographene platelet (NGP)/polyimide (PI) film is inkjet printed with morphologically optimized NGP/poly (amic acid) hybrid-based nanocomposite ink. The ink is produced with high-shear liquid phase exfoliation from inexpensive bulk graphite, manifesting good printability and high graphene concentration as high as 13.1 mg mL −1 . Featuring an ultra-thin thickness (∼1 μm only), the inkjet-printed NGP/PI film sensor is demonstrated to possess excellent thermal stability and high adhesive strength reaching the American Society for Testing and Materials 5B level. The highly uniform and consolidated NGP/PI nanostructure in the sensor enables the formation of π-π interaction between NGPs and PI polymer matrix, and the quantum tunneling effect is triggered among NGPs when ultrasound traverses the sensor. This sensing mechanism endows the NGP/PI sensor with good sensitivity, fidelity and accuracy, showing comparable performance as prevailing commercial ultrasound sensors such as piezoelectric sensors. The film sensor has a proven gauge factor as high as 739, when sensing ultrasound at 175 kHz, and an ultrabroad responsive spectrum up to 1.6 MHz. Graphical abstract: Image 1 Highlights: A novel film-type graphene/polyimide ultrasound sensor developed using full inkjet printing. A cost-efficient method for fabricating highly concentrated and stable graphene-based ink. Demonstrated capability of accurately sensing ultrasound in a regime of megahertz. Unique sensing mechanism by quantum tunneling effect and π-π interaction. Proven excellent thermal stability and extraordinary adhesive strength.