Tunable Fabrication of Conductive Ti₃C₂T_x MXenes via Inflating a Polyurethane Balloon for Acute Force Sensing

Abstract

Conductive microwrinkles present a superior performance in ultrasensitive sensing, smart controlling, as well as energy conservation because of their unique structures. These wrinkles are usually prepared by the deposition of a thin conductive stiff layer on a soft substrate under a certain strain. However, traditional conductive materials may encounter some deficiencies, such as fragility or poor dispersity, in any solvent. To promote the applicability of conductive microwrinkles, here, we adopt a new twodimensional nanomaterial Ti 3 C 2 T x MXene as the conductive stiff layer to construct the microwrinkles. By combining the spraying and inflating techniques, the hierarchical complex and delicate Ti 3 C 2 T x −polyurethane (Ti 3 C 2 T x −PU) microwrinkles have become facilely available. The characteristic wavelength and amplitude of the microwrinkles could be easily adjusted by altering the inflating height of the PU film or the spraying volume of the Ti 3 C 2 T x solution. Because the as-prepared Ti 3 C 2 T x wrinkles could sensitively generate deformation inducing a resistance change under a force, these structures are also assembled to detect the applied force. The Ti 3 C 2 T x force sensors showed quick response to a tiny force and stable reliability over hundreds of cycles, which hold a promising potential to monitor or employ the microforce.

Sensing with MXenes: Progress and Prospects

“…Han et al prepared a nontextile surface template with a wrinkled morphology formed through the inflation of a PU balloon. [104] MXenes were spray-coated on an inflated soft PU surface, which was subsequently deflated to form a hierarchical complex and microwrinkles on the PU surface and MXene coating. Furthermore, Gao et al designed a microstructured PET substrate to confine MXenes in channels.…”

Recent Progress in Ti3C2Tx MXene-Based Flexible Pressure Sensors

“…86 Combining spraying technology with a PU base can yield a Ti 3 C 2 T x /PU pressure sensor with micro-wrinkle structure, which makes the sensor produce obvious and fast resistance response under a tiny force (Figure 6b). 100 Furthermore, adding positively charged substances such as chitosan can yield a stronger binding force between MXene and PU, which endows sensor with better stability (Figure 6c). 101 Cellulose is a natural polymer material with a large aspect ratio, which can improve the mechanical strength of the sensor.…”

“…The mechanical properties and sensitivity of an MXene/PU composite prepared by depositing are greatly improved, with ability to detect an unknown position of an object and human gestures (Figure a) . Combining spraying technology with a PU base can yield a Ti 3 C 2 T x /PU pressure sensor with micro-wrinkle structure, which makes the sensor produce obvious and fast resistance response under a tiny force (Figure b) . Furthermore, adding positively charged substances such as chitosan can yield a stronger binding force between MXene and PU, which endows sensor with better stability (Figure c) .…”

Hierarchical Wrinkles for Tunable Strain Sensing Based on Programmable, Anisotropic, and Patterned Graphene Hybrids

“…Moreover, at most 5% variation in resistance within 100% strain is sufficient for most stable resistance devices. This straininsensitive property is caused by the combination of structure and pattern, and so, the use of nanomaterials with better conductivity (such as RGO with better reducing degree [40], Ti 3 C 2 T x MXene [41], or carbon nanotube (CNT) thin film [42]) can expand the application of this structure in the fields of stretchable electrodes and resistance stable conductivity. Based on the above experimental, patterns of striped lines, diagonal grids, and wavy lines were designed to obtain the required GF, as shown in Figure 13.…”