OBSERVATION OF SELF-PUMPED PHASE CONJUGATION WITH HIGH REFLECTIVITY AND FAST RESPONSE IN Cu-DOPED KNSBN CRYSTAL

Self-pumped phase conjugation （SPPC） is completely self-contained and requires no external mirrors, pumping beams or applied electric fields. Because of its simplicity and high reflectivity, SPPC has a host of potential applications including correcting spatial phase distortion, and optical image processing. At the present time, SPPC has been realized in BaTiO3, KNbO3, Ce-doped SBN and KNSBN single crystals. The KNSBN

Crystal growth and high reflectivity self-pumped phase conjugation of (Cu, Ce)-doped (KNa)_(0.1)(Sr_(0.6)Ba_(0.4))_(0.9)Nb_2O_6 crystal

Potassium sodium strontium barium niobate (KNSBN) crystal is one of the important photorefractive ferroelectric crystal materials, not only having good photorefractive properties, but also many advantages over other photorefractive crystal materials: (ⅰ) it is easy to grow in large size, (ⅱ) neither twinning nor poling problems exist; (ⅲ) it can accommodate a wide range of solution; (ⅳ) it is easy to be doped with many kinds of dopants.

Wettability Pattern for Ultrafast Water Self‑Pumping on Cemented Carbide Surface

A facile method to fabricate wettability pattern(two extreme wettabilities arranged in a pattern)to realize water self-pumping is proposed on cemented carbide while not necessarily depositing other materials on substrate surface.The water self-pumping is achieved by arranging wedge shaped superhydrophilic domain in superhydrophobic substrate using laser machining.Through single factor experiments,it is found that the key to the extreme wettabilities,micro⁃and nano⁃structures,is rendered by laser machining processes and is influenced by laser parameters.Meanwhile,the proper laser parameters that are used to fabricate required micro-and nano⁃structures are obtained.Finally,the water transport experiment is carried out,which shows that the velocity of water bulge could be up to 362 mm/s when the wedge angle is 3°.The mechanism of the water self-pumping is analyzed and it is found that the migration of water bulge is governed by Laplace pressure of the water bulge induced by the wedge micro-groove.

Finger-actuated wireless-charging wearable multifunctional sweatsensing system for levodopa and vitamin C

Efficient portable wearable sweat sensors allow the long-term monitoring of changes in the status of biomarkers in sweat,which can be useful in diagnosis,medication,and nutritional assessment.In this study,we designed and tested a wireless,battery-free,flexible,self-pumping sweat-sensing system that simultaneously tracks levodopa and vitamin C levels in human sweat and detects body temperature.The system includes a microfluidic chip with a self-driven pump and anti-reflux valve,a flexible wireless circuit board,and a purpose-designed smartphone app.The microfluidic chip is used for the efficient collection of sweat and the drainage of excess sweat.The dual electrochemical sensing electrodes in the chip are modified with functional materials and appropriate enzymatic reagents,achieving excellent selectivity and stability.The sensitivities of the levodopa sensor and the vitamin C sensor are 0.0073 and 0.0018μA·μM^(-1),respectively,and the detection correlation coefficients of both exceed 0.99.Both sensors have a wide linear detection range of 0–100 and 0–1000μM,respectively,and low detection limits of 0.28 and 17.9μM,respectively.The flexible wireless circuit board is equipped with the functions of wireless charging,electrical signal capture and processing,and wireless transmission.The data recorded from each sensor are displayed on a smartphone via a self-developed app.A series of experimental results confirmed the reliability of the sweat-sensing system in noninvasively monitoring important biomarkers in the human body and its potential utility in the comprehensive assessment of biological health.

Photorefractive Material KNSBN:Cu

This paper reports systematically the crystal growth and photorefractive properties of Cu-doped KNSBN, and the mechanism of the Cu ions' effects on the photorefractive properties of KNSBN. The Cu ions doped in KNSBN can form two energy levels in the band gap, thus play important roles in the photorefractive process. They increase the effective electron combination center concentration, which results in the modification of the photorefractive properties of KNSBN. The two-wave coupling gain coefficient of KNSBN: Cu is two times greater than that of KNSBN. The photorefractive sensitivity of Cudoped KNSBN is estimated to be in the order of 10^(-3) cm^2/J. Its cat-SPPC reflectivity can reach 65％ corresponding to an response time less than 8 s.