查找使用阿拉丁产品的科研文献

A variable-stiffness and healable pneumatic actuator

Hong-Qin Wang,Zi-Yang Huang,De-Wei Yue,Fang-Zhou Wang,Cheng-Hui Li

Pneumatic-powered actuators are receiving increasing attention due to their widespread applications. However, their inherent low stiffness makes them incompetent in tasks requiring high load capacity or high force output. On the other hand, soft pneumatic actuators are susceptible to damage caused by over-pressuring or punctures by sharp objects. In this work, we designed and synthesized a coordination adaptable network (PETMP-AIM-Cu) with high mechanical rigidity (Young's modulus of 1.9 GPa and elongation <2% before fracturing) as well as excellent variable stiffness property (soft-rigid switching ability σ as high as 3 268 000 when ΔT = 90 °C). Combining PETMP-AIM-Cu with a self-healing elastomer based on dynamic disulfide bonds (LP-PDMS), we fabricated a new pneumatic actuator which shows high load capacity at room temperature, but can also easily deform upon heating and thus can be actuated pneumatically. Benefiting from the excellent self-healing ability of PETMP-AIM-Cu and LP-PDMS, the entire pneumatic actuator can still be actuated after being cut and healed. Such a variable-stiffness and healable pneumatic actuator would be useful for complex environmental applications.

Small-Sized, Lightweight, and Flexible Triboelectric Nanogenerator Enhanced by PTFE/PDMS Nanocomposite Electret

Ze Bin Li,Hua Yang Li,You Jun Fan,Lu Liu,Yang Hui Chen,Chi Zhang,Guang Zhu

The rapid development of flexible and wearable electronics calls for a sustainable solution of the power supply. In recent years, the energy-harvesting triboelectric nanogenerator (TENG) has attracted increasing attentions due to its sustainability, flexibility, and versatility. However, achieving both high electric output and flexibility at the same time remains to be a challenge. In this work, we reported a corona charging enhanced flexible triboelectric nanogenerator (EF-TENG) to harvest mechanical energy from human motions. The EF-TENG relied on the repeated contacts between a poly(tetrafluoroethylene)/poly(dimethylsiloxane) nanocomposite electret and a nanofibers/AgNWs electrode on arrayed silicone pyramids. When the EF-TENG (3.5 × 3.5 cm2) was pressed, the open-circuit voltage (Voc), the short-circuit current (Isc), and the power density could reach 275 V, 9.5 μA, and 802.31 mW/m2, respectively. The Voc of the EF-TENG was improved by 244% compared to the device of which the electret was not corona charged. Major factors that affected the electric output of the EF-TENG were discussed, including the height of the pyramids, the configuration of the pyramids array, and the properties of the electret nanocomposite. The EF-TENG only had an overall thickness of 1.3 mm and a weight of 1.7 g, making it especially suitable to be attached onto human body for harvesting mechanical energy from biomechanical motions.

Fatigue-Resistant Polystyrene Microsphere Nanoarray Strain Sensors Based on the PDMS Flexible Substrate

Chen Wang,Jianye Guang,Ruizhi Fan,Ming Lin,Jianuo Nie,Fang Wang,Wei Peng,Mengdi Lu

Flexible strain sensors have gained prominence in applications such as wearable devices, smart healthcare, and human motion monitoring due to their excellent adaptability and sensitivity. However, challenges such as high production costs and complex fabrication processes hinder their widespread commercial adoption. This study presented a fatigue-resistant polystyrene (PS) microsphere nanoarray optical strain sensor based on a polydimethylsiloxane flexible substrate, fabricated using a simple hemispherical indentation-assisted method. The sensor exhibited exceptional stability, enduring over 950 cycles, and demonstrated remarkable durability and sensitivity (−0.371 nm/%) at stretching speeds of 62.5 μm/s. Finite element analysis, supported by the experimental data, clarified the mechanical behavior of PS nanoarrays under varying strain angles and analyzed the influence of these angles on the sensing spectrum. Besides, fatigue points caused by repeated use could be naturally recovered, with the restored sensor maintaining excellent stability. The results suggested that this proposed flexible nanostructure offered a high-performance, cost-effective, and straightforward manufacturing option for strain optical sensors.

A hierarchically layered porous PDMS-based pressure sensor with an ultrawide detection range

Haoshuo Wang,Xianglong Xia,Kezhen Fan,Chenlin Men,Peng Pan,Zhengchun Yang,Rui Zhang,Jie He,Huayi Li

A trilayer porous PDMS sensor with gradient porosity and modulus is developed for pressure sensing. • The sensor achieves a sensitivity of 4.87 kPa⁻¹ over 0–660 kPa with stable cycling performance. • The sensor enables wearable pulse monitoring and dual-channel PTT/PWV detection. Flexible pressure sensors for wearable biomedical applications require high sensitivity, a wide pressure detection range, and long-term mechanical stability. Here, we report a three-layer piezoresistive flexible pressure sensor with a hierarchical architecture and engineered composite materials. The device consists of a dense top layer, an intermediate porous layer, and a highly porous bottom layer based on a PDMS matrix. Conductive carbon fillers were selectively introduced to construct a CNT/CB-assisted conductive network, while ammonium bicarbonate was used as a sacrificial template to create the gradient porous structure. By tuning the ethyl cellulose/dibasic ester content (15 wt% and 7.5 wt%) in different layers, a modulus gradient along the thickness direction is achieved. This trilayer design enables progressive deformation and continuous reconstruction of conductive pathways under pressure, resulting in stable electrical responses over a broad pressure range. The sensor exhibits a sensitivity of 4.87 kPa −1 , calculated from the linear fitting slope of the loading branch over the full pressure range of 0–660 kPa, along with fast response and recovery times of approximately 60 and 80 ms, respectively. Moreover, excellent durability is demonstrated by stable performance over 5000 loading-unloading cycles. Owing to its capability to detect subtle pressure variations, the proposed sensor shows strong potential for wearable biomedical applications, particularly in physiological signal monitoring such as pulse detection. Download: Download high-res image (123KB) Download: Download full-size image

Selective Degradation of Polydimethylsiloxane (PDMS) Catalyzed by [Polydentate Ligand-Alkali Metal Fluoride] Complexes

Guangxin Chu,Yifu Zhang,Bo Yuan,Zeyu Zheng,Jingwen Xu,Zilong Zhang,Shengping Yi,Jun Liao,Chi Huang

Conventional base catalysts such as KOH often suffer from low yields and multiple side reactions in the degradation of polydimethylsiloxane (PDMS) to produce high-value dimethyl cyclosiloxane (DMC). To overcome these limitations, a novel supramolecular catalyst-[K(cryptand[2.2.2])]F-was designed and synthesized in this work by utilizing the coordination interaction between KF and cryptand[2.2.2]. In this structure, K⁺ forms a stable coordination bond with the cryptand, which effectively weakens the electrostatic interactions within KF, thereby significantly promoting the dissociation and nucleophilic reactivity of F⁻ in the organic phase and resulting in a highly efficient supramolecular catalytic system. The use of a DMSO/n-octadecyl alcohol mixed solvent not only facilitated a homogeneous reaction between PDMS and the catalyst but also reduced the solvation effect on F⁻, further enhancing its catalytic performance. Experimental results show that with only 1% [K(cryptand[2.2.2])]F loading, the cyclic monomer yield from PDMS cleavage reached 95%, with DMC selectivity exceeding 99.5%. Moreover, the catalyst retained high activity over ten consecutive cycles, maintaining a yield above 93% and demonstrating excellent stability. Additionally, an improved Dean-Stark trap was used to construct a continuous production system capable of synthesizing DMC under low solvent-circulation conditions. This study presents a new and efficient catalytic strategy for the green and high-value upcycling of silicone waste, offering promising prospects for advancing a circular economy in the silicone industry.

Synergistic antifouling coating based on PS-b-PDMS/CaO2 for marine aquaculture nets

Li Zhu,Sun Ningxin,Li Shiwei,Yang Jiaao,Guo Yi,Dong Lijie

Biofouling on marine aquaculture nets poses significant challenges to the economic viability and environmental sustainability of mariculture. This study developed a novel composite coating PS- b -PDMS/CaO 2 on the net surface by incorporating oxygen-releasing calcium peroxide nanoparticles (CaO 2 NPs) into a polystyrene-polydimethylsiloxane block copolymer (PS- b -PDMS). This coating synergistically combines low surface energy with a sustained oxygen-enriched microenvironment and enhanced reactive oxygen species (ROS) generation, resulting in significantly enhanced antifouling performance. Experiments demonstrated that the coating achieved outstanding antifouling efficacy, with antibacterial rates exceeding 99% against Escherichia coli, Staphylococcus aureus, and the marine bacterium Pseudomonas aeruginosa, anti-diatom adhesion rates of 92.18%, and anti-protein adhesion rates of 96.82%, with an optimal loading of 0.6 wt%. Moreover, the coating improved the mechanical properties (~ 35.53 MPa) while preserving the low-surface-energy characteristics and sustained oxygen release for over 60 h. A 90-day marine field test verified minimal biological fouling on the PS- b -PDMS/CaO 2 -0.6 coating surface, showing excellent real-sea antifouling performance and structural stability, indicating the long-term serviceability of aquaculture nets in marine environments. This study proposes a novel technical pathway for the development of environmentally friendly, long-term stable, and high-performance antifouling and antibacterial coatings that can effectively adapt to complex marine environments. Graphical abstract

Flexible Piezoresistive Sensor with High Stability Based on GO@PDMS-PU Porous Structure

Qingfang Zhang,Yi Li,Xingyu Wang,Xiaoyu Zhang,Shuyi Liu,Hengyi Yuan,Xiaodong Yang,Da Li,Zeping Jin,Yujian Zhang,Yutong Liu,Zhengmai Bian

In recent years, flexible piezoresistive sensors based on polydimethylsiloxane (PDMS) matrix materials have developed rapidly, showing broad application prospects in fields such as human motion monitoring, electronic skin, and intelligent robotics. However, achieving a balance between structural durability and fabrication simplicity remains challenging. Traditional methods for preparing PDMS flexible substrates with high porosity and high stability often require complex, costly processes. Breaking through the constraints of conventional material systems, this study innovatively combines the high elasticity of polydimethylsiloxane (PDMS) with the stochastically distributed porous topology of a sponge-derived biotemplate through biomimetic templating replication technology, fabricating a heterogeneous composite system with an architecturally asymmetric spatial network. After 5000 loading cycles, uncoated samples experienced a thickness reduction of 7.0 mm, while PDMS-coated samples showed minimal thickness changes (2.0–3.0 mm), positively correlated with curing agent content (5:1 to 20:1). The 5:1 ratio sample demonstrated exceptional mechanical stability. As evidenced, the PDMS film-encapsulated architecturally asymmetric spatial network demonstrates superior stress dissipation efficacy, effectively mitigating stress concentration phenomena inherent to symmetric configurations that induce matrix fracture, thereby achieving optimal mechanical stability. Compared to the pre-test resistance distribution of 10–248 Ω, after 5000 cyclic loading cycles, the uncoated samples exhibited a narrowed resistance range of 10–50 Ω, while PDMS-coated samples maintained a broader resistance range (10–240 Ω) as the curing agent ratio increased (from 20:1 to 5:1), demonstrating that increasing the curing agent ratio helps maintain conductive network stability. The 5:1 ratio sample displayed the lowest resistance variation rate attenuation—only 3% after 5000 cycles (vs. 80% for uncoated samples)—and consistently minimal attenuation at all stages, validating superior electrical stability. Under 0–6 kPa pressure, the 5:1 ratio device maintained a linear sensitivity of 0.157 kPa−1, outperforming some existing works. Human motion monitoring experiments further confirmed its reliable signal output. Furthermore, the architecturally asymmetric spatial network of the device enables superior conformability to complex curvilinear geometries, leveraging its structural anisotropy to achieve seamless interfacial adaptation. By synergistically optimizing material composition and structural design, this study provides a novel technical method for developing highly durable flexible electronic devices.

Slot-die coating of vinyl-PDMS composite membranes for alcohol perm-selective pervaporation

Fengkai Wang,Mengxin Shen,Zhangan Li,Yating Zhu,Jie Li,Naixin Wang,Hong Meng,Quan-Fu An

The use of pervaporation membranes has shown great potential in the extraction of bioethanol . However, a simple, continuous, and controllable alcohol perm-selective membrane manufacturing process is needed for practical applications. In this study, the slot-die coating technique was utilized to deposit low-viscosity vinyl-polydimethylsiloxane (vinyl-PDMS) and crosslinker onto a porous substrate . A defect-free separation layer could be created within just 20 min, which includes the membrane forming and drying process, due to the rapid hydrosilylation reaction between vinyl-PDMS and the crosslinker. Therefore, the efficient fabrication process is suitable for continuous roll-to-roll industrial production. Additionally, by optimizing the slot-die parameters, the thickness of the separation layer could be regulated from 0.4 to 15 μm. The obtained vinyl-PDMS composite membrane demonstrated a total flux of 2.8 kg m −2  h −1 and a separation factor of 10.3 for 5 wt% ethanol/water mixture at 60 °C.

Unravelling the Mechanism of Coloration and Prolonged Discoloration in Abnormally Thermochromic PDMS Nanocomposites

Yujie Peng,Peipei Shao,Ye Yuan,Jingru Mou,Ruitao Wen,Hong Chen,Ming Xiao

Traditional thermochromic materials prioritize high sensitivity and rapid discoloration. Reversible thermochromism with delayed discoloration is highly desirable for applications like thermal history indicators and energy-saving windows, yet it has rarely been achieved. Here, we construct such thermochromic composites simply by assembling hydrophobic silica nanoparticles in a polydimethylsiloxane (PDMS) matrix. The films transition from colorless and translucent to blue within minutes when heated above 60 °C and retain their blue color for over eight hours at 20 °C. Remarkably, the discoloration time can be further extended by lowering the environmental relative humidity. Integrating measurements of water absorption, refractive indices, and optical model calculation, we demonstrate the coloration rises from the combined effects of Rayleigh scattering and multiple scattering and the prolonged discoloration time is suprisingly caused by the gradual absorption of moisture. This unique thermochromic material opens new avenues for advancing thermochromic technology applications.

Preparation and Research of a Metal Anti-Corrosion Coating Based on PDMS Reinforcement

Chenyan Xie,Peng Dou,Gaojie Fu,Jiaqi Wang,Zeyi Wei,Xinglin Lu,Suji Sheng,Lixin Yuan,Bin Shen

Metal materials are widely used in power grid infrastructure, but they are prone to metal corrosion due to long-term exposure to various environmental conditions, resulting in significant losses. The existing superhydrophobic coatings have good anti-corrosion performance, but poor wear resistance. Therefore, it is extremely important to improve the wear resistance of superhydrophobic coatings. In this study, a kind of fluorine-modified SiO2particle was prepared with pentafluorooctyltrimethoxysilane (FAS-13) as the low surface energy modifier, following the fabrication of a superhydrophobic coating on metal substrate via a PDMS-doped spray deposition method to reinforcement wear resistance property. XPS, FT-IR and Raman spectra confirmed the successful introduction of FAS-13 on SiO2particles, as evidenced by the characteristic fluorine-related peaks. TGA revealed that the fluorine modified SiO2(F-SiO2) particles exhibited excellent thermal stability, with an initial decomposition temperature of 354 °C. From the perspective of surface morphology, the relevant data indicated a peak-to-valley height difference of only 88.7 nm, with Rq of 11.9 nm and Ra of 8.86 nm. And it also exhibited outstanding superhydrophobic property with contact angle (CA) of 164.44°/159.48°, demonstrating remarkable self-cleaning performance. And it still maintained CA of over 150° even after cyclic abrasion of 3000 cm with 800 grit sandpaper under a 100 g load, showing exceptional wear resistance. In addition, it was revealed that the coated electrode retained a high impedance value of 8.53 × 108Ω·cm2at 0.1 Hz after 480 h of immersion in 5 wt% NaCl solution, with the CPE exponent remaining close to unity (from 1.00 to 0.97), highlighting its superior anti-corrosion performance and broad application prospects for metal corrosion prevention.

3D-Printed PMN–PT/PDMS Piezoelectric Sensors with High Sensitivity for Intelligent Sensing

Xinhui Gao,Bingyu Huang,Yaqi Wang,Yongcheng Zhang,Shuzhi Sam Ge,Xiangxia Wei

Piezoelectric sensors have attracted great attention owing to their capability of directly converting mechanical stimuli into electrical signals. The properties of piezoelectric materials and their manufacturing techniques significantly impact the performance of a piezoelectric sensor. Herein, a piezoelectric composite is developed by integrating PMN–PT ceramic particles with superior piezoelectric properties into a flexible PDMS polymer matrix, and piezoelectric sensors with patterned structures are successfully fabricated via direct ink writing (DIW) 3D printing. It was demonstrated that the PMN–PT/PDMS piezoelectric sensor achieved a maximum sensitivity of 914 mV·N1–, which is approximately twice the values obtained from previous related studies. Moreover, the sensor is sensitive to structural variations, making it feasible to tune the piezoelectric output. This work demonstrates that 3D-printed piezoelectric sensors with rational structural design enable a more sensitive perception of mechanical stimuli, providing a viable strategy for intelligent security identification and human motion detection.

Construction of Superhydrophobic Surfaces Enhanced by Silanized-CNC-Assisted PVDF/PDMS Microsphere Coating

Coatings based on polyvinylidene fluoride (PVDF) and poly(dimethylsiloxane) (PDMS)-based polymeric microspheres can be easily fabricated via non-solvent-induced phase separation (NIPS) and electrostatic spraying (ES) techniques. Both techniques are promising strategies for constructing superhydrophobic surfaces on various substrates. However, PVDF and PDMS inherently suffer from severe aggregation, which generates oversized particles and inhomogeneous microstructures. Conventionally, costly and environmentally hazardous dispersants are required to alleviate this issue, severely restricting the industrial scalability and practical application of such coatings. In this work, methyltrimethoxysilane-modified cellulose nanocrystals (Si-CNCs) were introduced as a green multifunctional modifier to tackle these issues. The results revealed that as structural building blocks and dispersants, Si-CNCs inhibited polymer aggregation via electrostatic repulsion and steric hindrance, refined the particle size and formed uniform micro/nano hierarchical structures. Increasing Si-CNC loading further improved polymer dispersion and superhydrophobic performance. Coatings fabricated by ES showed better hydrophobicity than those fabricated by NIPS. ES achieved a water contact angle (WCA) of 160–166° and a sliding angle (SA) near 1° on cotton fabric, while NIPS had a WCA of 153.8–158° and an SA of around 2°. Wood and glass substrates also obtained favorable superhydrophobicity, with WCAs above 150° and SAs below 1°. Furthermore, all modified surfaces exhibited excellent abrasion resistance. This work provides a relatively eco-friendly, environmentally sustainable, scalable and substrate-flexible strategy for fabricating high-performance PVDF/PDMS-based superhydrophobic coatings.