Abstract Rubber based conductive composites with laminated structures are promising approaches to prepare flexible sensors with high performance abilities. Herein we report a facile one-step method to prepare polydimethylsiloxane (PDMS) based flexible strain sensors with a laminated structure via filler sedimentation. Nickel coated graphite (NCG) conductive fillers were homogenosly dispersed into a PDMS solution and then allowed to form a sedimention layer by allowing the mixture to stand for 2 h to obtain composite sensors. PDMS/NCG composites presented a two dimensional conductive network with a low percolation value of 2.52 vol% and high conductivity of 148 S/m at 11.11 vol% NCG. Due to the laminated structure, the Younge's modulus of the composites increased from 0.88 MPa for pure PDMS to only 1.98 MPa for 11.11 vol% NCG indicating high flexibility. Under applied stress, composite resistances increased from 8 to 20 Ω (varied by vol% NCG) to 4 × 108 Ω and presented a gauge factor (GF) of 5.6 × 108, amongst the highest values when compared with published results. Composite resistance under strain is explained by constriction, tunneling, and hopping mechanisms, and experimental results agree well with theoretical values. Filler sedimentation is demonstrated to be a valuable method to produce highly conductive and sensitive rubber based, laminated flexible sensors requiring only one preparation step.

中文翻译：

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通过填料沉降轻松一步制备具有高电导率和灵敏度的基于层压 PDMS 的柔性应变传感器

摘要 具有层压结构的橡胶基导电复合材料是制备具有高性能能力的柔性传感器的有前途的方法。在此，我们报告了一种简便的一步法，通过填料沉降制备具有层压结构的基于聚二甲基硅氧烷 (PDMS) 的柔性应变传感器。将镀镍石墨 (NCG) 导电填料均匀分散到 PDMS 溶液中，然后通过让混合物静置 2 小时形成沉淀层以获得复合传感器。PDMS/NCG 复合材料呈现二维导电网络，在 11.11 vol% NCG 下具有 2.52 vol% 的低渗透值和 148 S/m 的高电导率。由于层状结构，复合材料的杨氏模量从纯 PDMS 的 0.88 MPa 增加到 11 的仅 1.98 MPa。11 vol% NCG 表明具有高灵活性。在施加应力下，复合电阻从 8 Ω 增加到 20 Ω（随 vol% NCG 变化）增加到 4 × 108 Ω，并呈现出 5.6 × 108 的应变系数 (GF)，与已发表的结果相比，属于最高值。应变下的复合电阻可以通过收缩、隧道和跳跃机制来解释，实验结果与理论值非常吻合。填料沉降已被证明是生产高导电性和灵敏的橡胶基层压柔性传感器的一种有价值的方法，只需一个准备步骤。应变下的复合电阻可以通过收缩、隧穿和跳跃机制来解释，实验结果与理论值吻合良好。填料沉降已被证明是生产高导电性和灵敏的橡胶基层压柔性传感器的一种有价值的方法，只需一个准备步骤。应变下的复合电阻可以通过收缩、隧道和跳跃机制来解释，实验结果与理论值非常吻合。填料沉降已被证明是生产高导电性和灵敏的橡胶基层压柔性传感器的一种有价值的方法，只需一个准备步骤。