 |
| 柔軟的 Credit: Jiesheng Ren |
環保石墨烯布料實現可穿戴電子概念
科學家以石墨烯為基底的油墨生產出製造穿戴式裝置所需要的導電棉紡織品，採用新一代不含昂貴且有毒的化學加工的方法，為柔軟的可穿戴電子產品開創了新的紀元。
這類穿戴式紡織的電子產品為柔軟性電路、醫療保健、環境監測、能量轉換等提供了新的可能性。劍橋大學劍橋石墨烯中心（CGC）的研究人員與中國江南大學的科學家合作，設計了一種將石墨烯基油墨沉積在棉花上以生產導電紡織品的方法。這項企劃被發表在Carbon雜誌上，以導電棉生產的可穿戴式運動傳感器做展示。
棉，是長期用於服裝和紡織品中最普遍的，擁有透氣、柔軟及容易洗滌等特性。這些特性也使棉成為紡織電子產品的理想選擇。CGC的Felice Torrisi博士和他的研發團隊，通過用石墨烯基導電油墨浸漬導電棉織物的創新技術，大幅降低成本，並增長持久性和環保。
以Torrisi博士針對柔軟穿戴電子石墨烯油墨的技術作為基礎，該團隊創造新的化學油墨改質技術，比未改質的石墨烯更能粘附到棉纖維上。再將油墨沉積在織物上之後的熱處理，大幅加強了石墨烯的導電性。石墨烯對棉纖維的粘附性改質方式有點類似棉的染整方式，並且讓織物在經過幾次洗滌後仍然保持導電性。
雖然世界各地的許多研究人員已經開發出可穿戴裝置，但是大多數現有的可穿戴技術仍然仰賴將電子器材固定在然軟的材料上（例如塑料膜或紡織品）。這樣不但限制了與皮膚的接觸，且在穿著上也不舒服，不容易洗滌。
Torrisi博士解釋說：“大部分現有的導電油墨是由貴金屬（如銀）製成，這使得它們生產起來非常昂貴，且不持久，而石墨烯既便宜又環保，並與棉製品兼容。
江南大學合作作者王朝海教授補充說：“這種方法將允許我們將電子系統直接放入布料，這是一種令人難以置信的智能紡織品嵌入技術。
Torrisi博士和王教授與學生Tian Carey和Jeesheng Ren共同完成的此項新技術，預計將為個人健康技術、機能性運動服飾、作戰用軍用服裝、穿戴式技術運算等領域打開了以石墨烯的油墨技術為基礎的機能時尚與市場。
“將棉纖維轉化為功能性電子元件，將可以開拓一個全新的應用，從醫療保健到物聯網，”Torrisi博士說：“由於納米技術發達，預計在未來衣服都可以使用入這些紡織電子技術，並且與身體互動。”
石墨烯是單原子厚膜形式的高導電碳分子。該研發小組的工作是以散列中小於1納米厚的微小石墨烯片水分子，在化學改質的過程中將分子重新排序，並將它們粘附到棉纖維上，進而將石墨烯片均勻的形成一片極薄的導電網絡。這種以石墨烯分子附著的智能棉織物裝置經測試可承受多達500個運動週期，即使在正常洗衣機中也能超過10次洗滌次數。
這項研究技術得到歐洲研究委員協會、中國國家自然科學基金會國際研究獎學金和中國科學技術部的資助與支持。該技術也正透過劍橋大學的企業化相關部門朝向商用生產市場。
以上內容由ACOTEX服裝布料知識網編輯翻譯
【相關文章】
》「台灣紡織業是科技業，剛剛開始而已！」侯博明掌人纖公會
》北科大開發紡織產業塗佈技術 瞄準每年數百億商機
》研究人員開發出新的太陽能紡織技術 | University of Wisconsin-Madison researchers team up to develop solar textiles
》石墨烯(Graphene)的提出顛覆了穿戴式科技的遊戲規則 | Shaping The Future Of Wearables: New Technique Embeds Flexible Graphene Electrodes Into Clothes
 |
| Electron microscopy image of a conductive graphene/cotton fabric. Credit: Jiesheng Ren |
Environmentally-friendly graphene textiles could enable wearable electronics
A new method for producing conductive cotton fabrics using graphene-based inks opens up new possibilities for flexible and wearable electronics, without the use of expensive and toxic processing steps.
Wearable, textiles-based electronics present new possibilities for flexible circuits, healthcare and environment monitoring, energy conversion, and many others. Now, researchers at the Cambridge Graphene Centre (CGC) at the University of Cambridge, working in collaboration with scientists at Jiangnan University, China, have devised a method for depositing graphene-based inks onto cotton to produce a conductive textile. The work, published in the journal Carbon, demonstrates a wearable motion sensor based on the conductive cotton.
Cotton fabric is among the most widespread for use in clothing and textiles, as it is breathable and comfortable to wear, as well as being durable to washing. These properties also make it an excellent choice for textile electronics. A new process, developed by Dr Felice Torrisi at the CGC, and his collaborators, is a low-cost, sustainable and environmentally-friendly method for making conductive cotton textiles by impregnating them with a graphene-based conductive ink.
Based on Dr Torrisi's work on the formulation of printable graphene inks for flexible electronics, the team created inks of chemically modified graphene flakes that are more adhesive to cotton fibres than unmodified graphene. Heat treatment after depositing the ink on the fabric improves the conductivity of the modified graphene. The adhesion of the modified graphene to the cotton fibre is similar to the way cotton holds coloured dyes, and allows the fabric to remain conductive after several washes.
Although numerous researchers around the world have developed wearable sensors, most of the current wearable technologies rely on rigid electronic components mounted on flexible materials such as plastic films or textiles. These offer limited compatibility with the skin in many circumstances, are damaged when washed and are uncomfortable to wear because they are not breathable.
"Other conductive inks are made from precious metals such as silver, which makes them very expensive to produce and not sustainable, whereas graphene is both cheap, environmentally-friendly, and chemically compatible with cotton," explains Dr Torrisi.
Co-author Professor Chaoxia Wang of Jiangnan University adds: "This method will allow us to put electronic systems directly into clothes. It's an incredible enabling technology for smart textiles."
The work done by Dr Torrisi and Prof Wang, together with students Tian Carey and Jiesheng Ren, opens a number of commercial opportunities for graphene-based inks, ranging from personal health technology, high-performance sportswear, military garments, wearable technology/computing and fashion.
"Turning cotton fibres into functional electronic components can open to an entirely new set of applications from healthcare and wellbeing to the Internet of Things," says Dr Torrisi "Thanks to nanotechnology, in the future our clothes could incorporate these textile-based electronics and become interactive."
Graphene is carbon in the form of single-atom-thick membranes, and is highly conductive. The group's work is based on the dispersion of tiny graphene sheets, each less than one nanometre thick, in a water-based dispersion. The individual graphene sheets in suspension are chemically modified to adhere well to the cotton fibres during printing and deposition on the fabric, leading to a thin and uniform conducting network of many graphene sheets. This network of nanometre flakes is the secret to the high sensitivity to strain induced by motion. A simple graphene-coated smart cotton textile used as a wearable strain sensor has been shown to reliably detect up to 500 motion cycles, even after more than 10 washing cycles in normal washing machine.
The use of graphene and other related 2D materials (GRMs) inks to create electronic components and devices integrated into fabrics and innovative textiles is at the centre of new technical advances in the smart textiles industry. Dr Torrisi and colleagues at the CGC are also involved in the Graphene Flagship, an EC-funded, pan-European project dedicated to bringing graphene and GRM technologies to commercial applications.
Graphene and GRMs are changing the science and technology landscape with attractive physical properties for electronics, photonics, sensing, catalysis and energy storage. Graphene's atomic thickness and excellent electrical and mechanical properties give excellent advantages, allowing deposition of extremely thin, flexible and conductive films on surfaces and – with this new method – also on textiles. This combined with the environmental compatibility of graphene and its strong adhesion to cotton make the graphene-cotton strain sensor ideal for wearable applications.
The research was supported by grants from the European Research Council's Synergy Grant, the International Research Fellowship of the National Natural Science Foundation of China and the Ministry of Science and Technology of China. The technology is being commercialised by Cambridge Enterprise, the University's commercialisation arm.
Original Article: Phys.org
