ABSTRACT
An integrated solution providing a bi-stable antenna with reconfigurable performance and light-responsive behavior is presented in this paper for the first time. The proposed antenna includes a radiation layer with conductivity, which is integrated onto the bi-stable substrate. First, the effect of the radiation layer material and substrate layer parameters on antenna performance was studied. The experiment showed that an antenna with CNTF has a wider impedance bandwidth than one with CSP, namely 10.37% versus 3.29%, respectively. The resonance frequency increases gradually with the increase in fiber laying density and fiber linear density. Second, the influence of state change of the substrate layer on the antenna radiation pattern was studied. The measured results showed that the maximum radiation angle and gain of states I and II are at 90°, 1.21 dB and 225°, 1.53 dB, respectively. The gain non-circularities of the antenna at states I and II are 4.48 dB and 8.35 dB, respectively, which shows that the antenna has good omnidirectional radiation performance in state I. The display of the array antenna, which shows that the array antenna has good omnidirectional radiation performance in state A, with gain non-circularities of 4.20 dB, proves the feasibility of this bi-stable substrate in reconfigurable antennas. Finally, the antenna deforms from state I to state II when the illumination stimulus reaches 22 s, showing good light-responsive behavior. Moreover, the bi-stable composite antenna has the characteristics of small size, light weight, high flexibility, and excellent integration.
ABSTRACT
Although Ti3C2Tx MXene/fabric composites have shown promise as flexible pressure sensors, the effects of MXene composition and structure on piezoresistive properties and the effects of the textile structure on sensitivity have not been systematically studied. Herein, impregnation at room temperature was used as a cost-effective and scalable method to prepare composite materials using different fabrics [plain-woven fabric, twill-woven fabric, weft plain-knitted fabric, jersey cross-tuck fabric, and nonwoven fabric (NWF)] and MXene nanosheets (Ti3C2Tx, Ti2CTx, Ti3CNTx, Mo2CTx, Nb2CTx, and Mo2TiC2Tx). The MXene nanosheets adhered to the fabric surface through hydrogen bonding, resulting in a conductive network structure. The Ti3C2Tx@NWF composite was found to be the optimal flexible pressure sensor, demonstrating high sensitivity (6.31 kPa-1), a wide sensing range (up to 150 kPa), fast response/recovery times (300 ms/260 ms), and excellent durability (2000 cycles). Furthermore, the sensor was successfully used to monitor full-scale human motion, including pulse, and a 4 × 4 pixel flexible sensor array was shown to accurately locate pressure and recognize the pressure magnitude. These findings provide a basis for the rational design of MXene/textile composites as wearable pressure sensors for medical diagnosis, human-computer interactions, and electronic skin applications.
ABSTRACT
Vitiligo is a common, psychologically devastating pigmentary disorder. Surgical graftings are used to treat stable vitiligo when medical treatment fails. An automated epidermal micrograft harvesting (AEMH) system was first designated to treat wounds, and very few studies investigated the application of AEMH in vitiligo. In this study, we investigated the efficacy and safety of the AEMH system in patients with stable segmental and nonsegmental vitiligo. The rate of repigmentation and adverse events was recorded bimonthly for at least 12 months. We analyzed the efficacy based on patient characteristics, vitiligo subtypes, and different anatomical locations. A total of 56 depigmented lesions from 34 patients were included. 95.50% of the automated epidermal micrografts were successfully grafted at the recipient sites. There was a significant improvement in Vitiligo Area Scoring Index (VASI) and Dermatologic Life Quality Index (DLQI) in patients treated with AEMH (p < 0.001). The rate of repigmentation by VASI score improves from 96.25 ± 8.59 to 48.30 ± 28.16 after the treatment (p < 0.001). Treatment outcomes were comparable between the patients of segmental and stable nonsegmental vitiligo. The face and neck region achieved a better outcome, followed by the trunk (chest, abdomen, back, and axilla), limbs, and the worse outcome was found in the acral region (p < 0.014). Conclusively, AEMH is an effective treatment procedure with limited adverse events in patients with stable vitiligo. This harvesting method may be a feasible option for vitiligo surgical treatment.
