Environmentally Stable and Self-Recovery Flexible Composite Mechanical Sensor Based on Mechanoluminescence

Abstract

Mechanoluminescent materials featuring mechanical-to-optical conversion have been vigorously studied as a carrier of optical sensing technology in the field of mechanical sensing due to their self-recovery, visualization, and non-contact sensing characteristics. However, the impact of the human living environment such as temperature, humidity, corrosive substances, etc. on optical sensing materials cannot be ignored, which greatly affects the accuracy of optical sensing. To overcome these barriers to the accuracy of these factors, a flexible mechanoluminescent composite device with high brightness in a bright and dark environment based on Ce 3+ -doped garnet structure phosphors Tb 3 Al 5 O 12 was proposed. Under the action of repeated mechanical stimulation, the mechanoluminescence (ML) intensity presents good self-recovery performance, and the ML intensity shows a zerothermal-quenching performance in the range of 0−100 °C. In addition, the evaluation of moisture resistance was performed under different durations in the water, proving that the intensity of ML can hardly be affected by the humid environment. Accordingly, a transmission system based on a robot finger was proposed to simulate the application of the human tactile system. The results showed great potential for Tb 3 Al 5 O 12 : Ce 3+ -based ML composite devices in advanced optical multimode sensors to promote their diversified application.

Insights into blue-light activated red-emitting persistent luminescence from Pr3+-doped phosphors

“…To verify the phase purity and crystal structures of the CCGGO: xPr 3+ samples, the Rietveld refinement technique was used based on Y 3 Ga 2 Al 3 O 12 (ICSD#280107) as the original structural model. 28,29 As shown in Fig. 1a, the observed XRD pattern (black cross) matches well with the calculated one (red solid line), and no impure phase was observed.…”

“…The result implies the d-spacing is 0.263 nm, which is consistent with the distance of the (332) plane of CCGGO:0.0015Pr 3+ . 20,28 As illustrated in the elemental mapping images (Fig. 2c-j), there are Ca, Cd, Ga, Ge, Pr, and O elements in CCGGO:0.0015Pr 3+ .…”

“…4c, the PLE spectra (monitor wavelength: λ em = 613 nm) of CCGGO:xPr 3+ (0.0001 ≤ x ≤ 0.0035) exhibit a broad excitation band centered at 300 nm and a series of peaks centered at 450, 461, 473 and 485 nm, respectively. 27,28,38 At the same time, the broad-band excitation centered at 300 nm is attributed to the 4f 2 → 4f5d transition of Pr 3+ , while additional sharp excitation peaks at 450, 461, 473 and 485 nm are the minor excitation peaks, that correspond to the 3 H 4 → 3 P 0 , 3 H 4 → 3 P 1 , 3 H 4 → 3 P 2 , and 3 H 4 → 1 I 6 transitions of Pr 3+ , respectively. 28,39 Fig.…”

A broadband yellow-green emitting mixed orthoborate–pyroborate phosphor, Ba2Sc2B4O11:Ce3+, for white light emitting diodes

“…Given the growing importance of energy saving and environmental friendliness, LED-based solid-state lighting devices have been regarded as replacements for existing lighting technologies in recent years. [1][2][3][4][5] Compared with traditional lighting devices such as incandescent and fluorescent devices, white light-emitting diodes (WLEDs) have received extensive attention due to their advantages of environmental friendliness, long service life, short response time and high energy efficiency. [6][7][8][9][10] Currently, the most common method for fabricating WLEDs is to coat yellow-emitting phosphors, such as Y 3 Al 5 O 12 :Ce 3+ (YAG:Ce 3+ ), on a blue LED chip.…”

Interface-Mediated Mechanoluminescence Enhancement from Heterojunction Phosphors: Experiment and Theory

“…Mechanoluminescence (ML) phosphors offering a unique light source by converting mechanical (tensile, compress, rub, etc.) energies to light emissions have attracted great interest in the last two decades due to their potential applications in wireless detection, anti-counterfeiting encryption, biological imaging, artificial skin, and night surveillance, among other fields. − The ML properties of the phosphors, for instance, the luminescence intensity, quantum yield, radiative lifetime, stability, and repeatability, are pivotal in determining their real-world applications. − However, the relatively weak ML intensity of the phosphors has remained as the problem to be solved.…”