Recoverable Dual-Modal Responsive Sensing Materials Based on Mechanoluminescence and Thermally Stimulated Luminescence toward Noncontact Tactile Sensors

Abstract

Tactile sensing with stress and temperature sensing as core elements have shown promising prospects in intelligent robots and the human–machine interface. Mechanoluminescence (ML)-based stress sensing can realize the direct sensing of mechanical stimulation, whereas indirect temperature sensing based on luminescent sensing materials usually requires the stimulation of extra light or force. Herein, a trap-controlled material Sr2MgAl22O36:Mn2+ with bifunctional mechano/thermal sensing applications was developed and investigated in detail. Visualized bright green-emitting ML and thermally stimulated luminescence (TSL) directly and rapidly responded to mechano/thermal dual stimulation in the Sr2MgAl22O36:Mn2+/PDMS composite film. It is worth mentioning that this study proposed a new idea of direct temperature sensing by the initial intensity of TSL due to thermal–photo energy conversion, unlike previous temperature sensor technology. Based on this, we designed a flexible optical skin with a simple structure and verified its application prospect as a tactile sensing material with dual mechano/thermal response, establishing a unique imaging mode and providing a convenient, reliable, and sensitive way to remotely visualize the distribution of stress and temperature. This study paves a new way for the development of optical skins with simple structures and sensitive visibility in the application of intelligent robot tactile sensing.

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

“…The reason for this thermal quenching phenomenon may be that the increase in temperature increases the number of high vibrational energy levels and the probability of non-radiative transitions between activator ions, which explains why the PL intensity decreased with the increase in temperature. 46 To further understand the temperature dependence properties of the photoluminescence of the phosphor Ba 2 Sc 2 B 4 O 11 :Ce 3+ , the Arrhenius equation was used for calculating the activation energy E a of thermal quenching. 47 where I 0 and I T represent the emission intensity of the phosphor at room temperature and the test temperature, respectively, E a represents the activation energy, A is a constant, and K is the Boltzmann constant (8.617 × 10 −5 ).…”

“…probability of non-radiative transitions between activator ions, which explains why the PL intensity decreased with the increase in temperature. 46 To further understand the temperature dependence properties of the photoluminescence of the phosphor Ba 2 Sc 2 B 4 O 11 :Ce 3+ , the Arrhenius equation was used for calculating the activation energy E a of thermal quenching. 47 Ln…”

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

“…7b, the relevant trap depth of the sample can be approximately obtained by the formula as follows:where E is the trap depth; T m is the peak temperature. 20,31 Based on the equation, the calculated trap depths are 0.684 and 0.776 eV, respectively. Generally speaking, the most suitable depth for the afterglow is 0.6–0.8 eV.…”

“…The reliability factors for the whole patterns are R p = 4.26%, R wp = 9.01%, and χ 2 = 1.77, demonstrating that the reliability results were reasonable. 18,30,31 And the unit cell parameters are a = b = c = 12.2033 (3) Å, V = 1817.32 (6) Å 3 . Fig.…”

Dynamic readout of optical information based on the color-tunable emitting electron-trapping material BaAl12O19:Eu2+ toward high security level optical data storage and anticounterfeiting

“…3 The mode of optical information readout is currently reported more based on thermally stimulated luminescence (TSL) or photostimulated luminescence (PSL) of deep traps. [4][5][6] In addition, although some materials can decode optical information by various readout modes, the readout information is relatively single and cannot truly achieve intensity wavelength multiplexed readout in a single medium. 7 Therefore, the dynamic readout of optical information (including intensity, wavelength, color, etc., multiplexed) is expected to improve the security level of optical information storage and information encryption.…”