A Route toward Ultrasensitive Layered Carbon Based Piezoresistive Sensors through Hierarchical Contact Design

Abstract

Ultrahigh sensitive piezoresistive sensors at small deformation are highly desired in many applications. Here, we propose a hierarchical contact design concept and implement it through a direct laser writing technique for fabricating layered carbon piezoresistive sensors with ultrahigh sensitivity. Sensors with unprecedented gauge factors (∼5000-10 000) at small deformation (ε < 0.1%) were successfully fabricated and demonstrated for their use in sensing both static and high-frequency (20-30 kHz) dynamic mechanical loads. A simple basic structure unit (BSU) contact network model was developed for understanding the importance of the BSU/BSU contact strength and network fractal dimension in dictating the piezoresistive sensitivity of the layered carbon piezoresistive sensors with designed hierarchical contact structures. The hierarchical contact design concept and the contact network model proposed in our work could open a general route for developing ultrasensitive piezoresistive sensors based on granular matter and composite materials.

Graphene‐Coated Spandex Sensors Embedded into Silicone Sheath for Composites Health Monitoring and Wearable Applications

“…It is desirable to lower the concentration of conductive filler to augment the sensor sensitivity while retaining stretchability of the polymer matrix. Albeit carbon nanomaterials have allowed ultralow percolation thresholds (with gauge factors (GF) as high as 4–5 orders of magnitude), a compromise should be made between GF and sensing range. In particular, this issue is of significance when it comes to wearable sensors wherein the sensor may undergo a wide range of strains as tiny as heart beat to rigorous joint motions .…”

Processing–structure–property relationship in direct laser writing carbonization of polyimide

“…The DLWc generated carbon patterns have found a variety of electrically related potential applications . To materialize this technique, the relationship of the processing‐structure‐electrical property involved in DLWc has to be established.…”

“…[1][2][3][4][5][6][7][8][9] With regard to the application of DLW for polymer carbonization, Tour et al [10] recently demonstrated the use of high-power CO 2 laser for in situ producing porous graphene structures from a commercial polymer-polyimide (DuPont Kapton HN). This new finding subsequently stimulated the interests of researchers from different fields in exploring and developing various novel applications by using direct laser writing of polyimide, including water splitting and fuel cell technology, [11] supercapacitors, [12][13][14][15][16] flexible electrodes, [17] heating elements, [18] various sensors for detecting/measuring sound, [14] strain or stress, [19][20][21] and different chemicals species. [13,[22][23][24] As compared to the traditionally adopted direct heating method for polymer carbonization, direct laser writing carbonization (DLWc) is able to create carbonized features/patterns in ambient environment with more flexibility, versatility, and highly controlled fashion.…”

Direct Laser Writing-Assisted Method for Template-Free Fabrication of Biomass-Based Porous Carbon Platelets with Uniform Size and Arbitrarily Designed Shapes

“…In contrast, there was no such behavior being observed for the similar carbon patterns fabricated by DLW on the commonly used polymer substrate—polyimide. 50,57 The flexibility of the DLW process along with the spontaneous detachment behavior of the carbon patterns formed on the CellP/NaLS composite sheet would allow a new process for easily fabricating freestanding PCPs of different shapes. For concept demonstration, in Figure 2a 1 , we show a snap-shot of the detachment of a popular Chinese-knot-shaped PCP from its parent CellP/NaLS composite sheet upon immersion in water.…”