PDMS Layer Research Articles

Robust and Eco-Friendly Superhydrophobic Starch Nanohybrid Materials with Engineered Lotus Leaf Mimetic Multiscale Hierarchical Structures

The use of superhydrophobic surfaces in a broad range of applications is receiving a great deal of attention due to their numerous functionalities. However, fabricating these surfaces using low-cost raw materials through green and fluorine-free routes has been a bottleneck in their industrial deployment. This work presents a facile and environmentally friendly strategy to prepare mechanically robust superhydrophobic surfaces with engineered lotus leaf mimetic multiscale hierarchical structures via a hybrid route combining soft imprinting and spin-coating. Direct soft-imprinting lithography onto starch/polyhydroxyurethane/cellulose nanocrystal (SPC) films formed micro-scaled features resembling the pillar architecture of lotus leaf. Spin-coating was then used to assemble a thin layer of low-surface-energy poly(dimethylsiloxane) (PDMS) over these microstructures. Silica nanoparticles (SNPs) were grafted with vinyltriethoxysilane (VTES) to form functional silica nanoparticles (V-SNPs) and subsequently used for the fabrication of superhydrophobic coatings. A further modification of PDMS@SPC film with V-SNPs enabled the interlocking of V-SNPs microparticles within the cross-linked PDMS network. The simultaneous introduction of hierarchical microscale surface topography, the low surface tension of the PDMS layer, and the nanoscale roughness induced by V-SNPs contributed to the fabrication of a superhydrophobic interface with a water contact angle (WCA) of ∼150° and a sliding angle (SA) of <10°. The PDMS/V-SNP@SPC films showed an ∼52% reduction in water vapor transmission rate compared to that of uncoated films. These results indicated that the coating served as an excellent moisture barrier and imparted good hydrophobicity to the film substrate. The coated film surfaces were able to withstand extensive knife scratches, finger-rubbing, jet-water impact, a sandpaper-abrasion test for 20 cycles, and a tape-peeling test for ∼10 repetitions without losing superhydrophobicity, suggesting superior mechanical durability. Self-cleaning behavior was also demonstrated when the surfaces were cleared of artificial dust and various food liquids. The green and innovative approach presented in the current study can potentially serve as an attractive new tool for the development of robust superhydrophobic surfaces without adverse environmental consequences.

Improved C3H6/C3H8 separation performance on ZIF-8 membranes through enhancing PDMS contact-dependent confinement effect

Polymer coating post-treatment strategy of the zeolitic imidazolate framework (ZIF) membranes offers a versatile and feasible opportunity to restrict the intrinsic flexibility of ZIF framework and improve their gas separation performance. Herein, two different coating methods (Vacuum-assisted drip coating (VADC) and Static drip coating (SDC)) are utilized to prepare PDMS/ZIF-8 composite membranes based on ZIF-8 membranes with different compactness (high, medium and low-quality membrane) for investigating the effect of the contact area between PDMS layer and ZIF-8 membrane on C3H6/C3H8 separation performance of PDMS/ZIF-8 composite membranes. The results reveal that the increase of the contact between PDMS layer and ZIF-8 membrane can enhance the contact confinement effect on the flexibility of ZIF-8 framework, resulting in a higher improvement of the separation performance for C3H6/C3H8 of PDMS/ZIF-8 composite membranes with pressure. The prepared composite membrane based on VADC method showed a significant improvement in C3H6/C3H8 separation factor (77–102) with slight increase in C3H6 permeance (about 10%) at feed pressure of 7 bar. Moreover, this facile vacuum-assisted drip strategy attenuated the impact of the quality of ZIF-8 membranes on fabrication reproducibility of the composite membranes, which can withstand high pressure. Therefore, this work advances ZIF-8 membrane moving forward to industrial C3H6/C3H8 separation.

(Invited) In-Vitro Studies on Nanomaterials and Anticancer Therapies Using Lab-on-a-Chip Microsystems

Introduction This presentation will focus on the lab-on-a-chip microsystems for different applications, ranging from cytotoxicity tests to the evaluation of the effectiveness of selected anticancer therapies. When in vitro tests are performed with the use of microsystems, manual activities that are required when seeding cells or administering solutions of tested compounds are eliminated. It allows for greater reproducibility and eliminates some limitations of studies conducted in the macroscale. Moreover, in microsystems it is possible to better reflect in vivo conditions and obtain a homogeneous (same size) population of multicellular spheroids (3D cell model) relatively easily [1]. This way, the results obtained in microfluidic systems can allow to better predict the response of an organism to the tested compounds/nanomaterials or applied anticancer treatment. Microsystems for in vitro studies The first stage in the development of a microsystems for in vitro studies is usually based on a selection of appropriate materials for their fabrication. Because non-toxic materials must be applied for this aim, glass and chosen polymers are among the most often used ones. In addition, the application of transparent materials enables observation of cell cultures during testing. The introduction of cells to microchambers, obtaining specific models of cell culture (monolayer or spheroids culture) as well as nutrient delivery to the cells is achieved thanks to the appropriate geometry of the microchannels and microchambers. In the framework of presented studies, microsystems u obtained by bonding several layers of PDMS or glass and PDMS will be discussed. Methods The cytotoxicity of selected nanomaterials (such as quantum dots or gold nanoparticles) was evaluated with the use of microsystems [2,3]. The research was carried out on two cell culture models (monolayer and spheroids) and the examination of cell viability was based on the fluorescence staining of live and dead cells or Alamar blue test. Additionally, the change in cell morphology during the conducted research was observed.Two types of therapeutic procedures were performed with the use of microsystems. These were photothermal therapy (PTT) [4] and electrochemotherapy (ECT). In the case of PTT, after 24 hours from the introduction of cells, a photoactive agent was introduced into the microsystem (gold nanoparticle solutions were used) and incubated for another 24 hours. After this time, the cell medium was passed through the microsystem to wash away the excess of nanoparticles that did not penetrate or bind to the cell membranes, then a laser irradiation was applied. The ECT procedure was carried out in a microsystem equipped with specially designed electrodes. The electrodes were arranged parallelly to each other and tangent to the culture microcells. After introducing the cytostatic compound into the microsystem, the cells were subjected to electric impulse. In this way, drugs were actively introduced into the cells. Results and Conclusions The conducted experiments allowed to evaluate the cytotoxicity of quantum dots for normal and tumor cell lines. As the tests were carried out for both 2D and 3D models, the obtained results were compared. The effectiveness of the PTT procedure carried out in a microsystem with the use of aptamer-modified nanoparticles was assessed. The procedure was found to be more effective in the case of breast cancer cells than for lung cancer cells. A microsystem for ECT was developed and the effectiveness of this method was compared to chemotherapy, which was also carried out in the microsystem. For drugs that poorly penetrate the membranes by endocytosis, the use of electrical impulses increases the amount of drug introduced into the cells.

Biomechanical Energy Harvester: Skin‐like Elastomer Embedded Zinc Oxide Nanoarrays for Biomechanical Energy Harvesting (Adv. Mater. Interfaces 10/2021)

An ultra-flexible and stretchable biomechanical energy harvester is developed by Zi Chen, Marc D. Feldman, John X. J. Zhang and co-workers as described in article number 2100094. The ZnO nanorod array is sandwiched by a layer of electrode (carbon nanotube) and biocompatible polymer PDMS. Piezoelectricity of ZnO will generate electricity across the two electrodes in response to mechanical deformation.

Lossy Mode Resonances Generated in Planar Configuration for Two-Parameter Sensing

This work shows a new sensor structure for simultaneous measurement of two parameters, temperature and refractive index. The optical configuration consists of incidence of light on the edge of a soda-lime coverslip fully coated with a CuO thin film and partially coated with a PDMS thick layer. This planar configuration permitted to generate two separated lossy mode resonances (LMRs): one centered at 600 nm and the other at 1000 nm. The second resonance is induced by the PDMS layer and it can be used to measure the temperature due to its high thermo-optic coefficient (the sensitivity is −1.75 nm/°C in the temperature range from 20 to 40 °C), whereas the first resonance is used for sensing refractive index with sensitivity of 1460 nm/RIU in the refractive index range from 1.3328 and 1.37. Finally, a calibration test was carried out using a calibrated oil series with refractive index ranging from 1.33 to 1.36. This work demonstrates the possibility of generating multiples resonances in a single structure as simple as a coverslip, which can be used as a multi-parameter interchangeable sensor, especially suitable for biological applications or the detection of heavy metals in water.

DNA tetrahedron-mediated immune-sandwich assay for rapid and sensitive detection of PSA through a microfluidic electrochemical detection system

Prostate-specific antigen (PSA) is the most widely used biomarker for the early diagnosis of prostate cancer. Existing methods for PSA detection are burdened with some limitations and require improvement. Herein, we developed a novel microfluidic–electrochemical (μFEC) detection system for PSA detection. First, we constructed an electrochemical biosensor based on screen-printed electrodes (SPEs) with modification of gold nanoflowers (Au NFs) and DNA tetrahedron structural probes (TSPs), which showed great detection performance. Second, we fabricated microfluidic chips by DNA TSP-Au NF-modified SPEs and a PDMS layer with designed dense meandering microchannels. Finally, the μFEC detection system was achieved based on microfluidic chips integrated with the liquid automatic conveying unit and electrochemical detection platform. The μFEC system we developed acquired great detection performance for PSA detection in PBS solution. For PSA assays in spiked serum samples of the μFEC system, we obtained a linear dynamic range of 1–100 ng/mL with a limit of detection of 0.2 ng/mL and a total reaction time <25 min. Real serum samples of prostate cancer patients presented a strong correlation between the “gold-standard” chemiluminescence assays and the μFEC system. In terms of operation procedure, cost, and reaction time, our method was superior to the current methods for PSA detection and shows great potential for practical clinical application in the future.

A highly reliable contact-separation based triboelectric nanogenerator for scavenging bio-mechanical energy and self-powered electronics

The increasing interest in harvesting mechanical energy from day-to-day activities is gaining huge interest among researchers. We have fabricated a triboelectric nanogenerator (TENG) made of aluminum and PDMS film acting as positive and negative triboelectric layers. The layers are arranged in an arc-shaped structure with an air gap of 1 cm between the layers of the device. The PDMS layer is made by blending the polymer solution with the hardener in an appropriate ratio and dried to make the transparent and flexible polymer film. The device shows a maximum electrical response of 110 V and 260 nA voltage and current with the power density of 2.9 mW/m2 at 100 MΩ load resistance. Further, the device has been used for lighting green LEDs and charging commercial capacitors. An Arduino board was connected with LED and buzzer, which was triggered by the TENG device. This shows that with the proper usage of electronic components TENG can be used for self-powered sensors and with IoT applications.

The enhancement of sensitivity and response times of PDMS-based capacitive force sensor by means of active layer modification

In this work, sensitivity and response times of PDMS-based capacitive force sensors are enhanced via the modifications of the PDMS layer. Two modifying approaches are proposed; (i) change PDMS’s (elastomer:curing agent) ratio and (ii) adding conductive polymer PEDOT:PSS into the PDMS layer. The change of PDMS (elastomer:curing agent) ratio from (10:1) to (30:1) increases the sensitivity from 0.4 ± 0.08 to 0.72 ± 0.23 kPa−1 (+80%) but it does not significantly affect the response/recovery times. In addition, by adding 1% wt. of PEDOT:PSS to PDMS (30:1), the further increment of sensitivity from 0.72 ± 0.23 to 1.44 ± 0.17 kPa−1 (+100%) and the shorter response time from 1.59 ± 0.02 to 0.45 ± 0.03 s (−72%) are observed. The mechanical and electrical studies reveal that the change of PDMS (elastomer:curing agent) ratio and the adding of PEDOT:PSS to PDMS layer result in the modification of PDMS’s deformability and the increase of charge transportation, leading to the enhancement of sensing characteristics of the sensors.

Superhydrophobic Candle Soot as a Low Fouling Stable Coating on Water Treatment Membrane Feed Spacers.

Membrane separation processes including reverse osmosis are now considered essential techniques for water and wastewater treatment, especially in water-scarce areas where desalination and water reuse can augment the water supply. However, biofouling remains a significant challenge for these processes and in general for marine biological fouling, which results in increased energy consumption and high operational costs. Especially in flat sheet membrane modules, intense biofilm growth occurs on the feed spacer at points of contact to the membrane surface. Here, we developed an ultrastable superhydrophobic antibiofouling feed spacer that resists biofilm growth. A commercial polypropylene feed spacer was coated with poly(dimethylsiloxane) (PDMS), and then, candle soot nanoparticles (CSNPs) were embedded into the ultrathin layer of PDMS, which resulted in a superhydrophobic nanostructured surface with a contact angle >150°. The CSNP-coated spacer was examined for inhibition of biofilm growth by a cross-flow membrane channel using Pseudomonas aeruginosa (PA01), and the coating was examined for effectiveness in marine fouling by testing the adhesion of marine bacterium Cobetia marina and diatom Navicula perminuta in a dynamic accumulation assay. In all cases, the CSNP coatings showed almost complete elimination of biofilm growth under the conditions tested. Confocal laser scanning microscopy and scanning electron microscopy indicated a 99% reduction in biofilm growth on the modified spacers compared to the uncoated controls. This effect was attributed to the superhydrophobic nanostructured surface, where trapped gasses formed a plastron on the coating. This plastron was observed to be extremely stable over time and could even be replenished at elevated temperatures. Development of similar antibiofouling coatings on feed spacers or other marine applications might lead to improvements in many industrial processes including membrane filtration where increased membrane life span and reduced energy consumption are key to implementation.

Solar-Assisted, Fast, and In Situ Recovery of Crude Oil Spill by a Superhydrophobic and Photothermal Sponge.

Development of a functional sorbent for effective crude oil absorption is essential to address large-scale spilling incidents. Herein, we demonstrate a facile method for preparing a superhydrophobic and photothermal PDMS/CuS/PDA@MF sponge through sequential depositions of PDA, CuS nanoparticles, and a PDMS layer onto a melamine sponge. The optimized composite sponge exhibits a superhydrophobic surface property, high absorption capacity for oils, robust recycling, and excellent photothermal conversion performance. Under sunlight irradiation, the sponge can be rapidly heat up for effectively reducing the viscosity of the surrounding crude oil in order to enhance its fluidity. As a result, uptake of crude oil can be achieved continuously at approximately 5.3 g/min using a peristaltic pump. Overall, we believe that a simple fabrication method from low-cost reagents and excellent crude oil remediation performance render the PDMS/CuS/PDA@MF sponge as an excellent sorbent candidate for remediating crude oil spill.

Slippery coatings with mechanical robustness and self-replenishing properties as potential application on magnesium alloys

Slippery liquid-infused surfaces (SLISs) have the same development potential and application prospects as superhydrophobic surfaces (SHSs) in the fields of corrosion resistance, anti-icing, anti-fouling and drag reduction. However, the durability of SLISs is still a challenge because of the migrating, evaporating, or leaking of the infused liquids. Herein, we proposed a durable polydimethylsiloxane/silicone oil (PDMS-oil) system with mechanical robustness and self-replenishing property. As a demonstration of potential application, the PDMS-oil coating was applied on the magnesium alloy for multi-functions. A layer of PDMS cross-linking network was first cured on the magnesium alloy surface, and then a certain amount of low viscosity dimethyl silicone oil was diffused into the PDMS layer to form the final SLIS coatings. It is found that 50 wt% of silicone oil content is more suitable for the PDMS-oil based slippery coating on Mg alloy, which can maintain a low ice shear strength of less than 30 kPa after 20 icing/deicing cycles and a lower sliding angle of about 30° after wear cycles (under a normal pressure of 10 kPa). Significantly, the proposed PDMS-oil based slippery coating possesses good corrosion resistance and self-replenishing ability, which can also withstand hot water, ice water, and corrosive solutions (i.e. acid and alkaline aqueous solutions). The Mg alloy with the PDMS-oil based slippery coating can remain intact in a 3.5 wt% NaCl aqueous solution even after 20 days at room temperature. It is believed that the Mg alloys with the proposed PDMS-oil based slippery coatings would have more potential applications even in severe environments.

High-efficient photoacoustic generation with an ultrathin metallic multilayer broadband absorber.

Metal nanomaterials have been widely used to generate photoacoustic (PA) signals because of their high optical absorption characteristics. However, the PA conversion efficiency of metal nanomaterials is limited by the single-wavelength absorption at the resonant peak. To mitigate this issue, a three-layer ultrathin film containing a thin PDMS layer sandwiched between two ultrathin chromium films is proposed. This kind of film structure can attain high optical absorbance (>80%) through the visible light range (450-850 nm). The optical absorption characteristics can be easily modulated by varying the thickness of the PDMS layer. Under the same excitation condition, the PA signal generated by this film structure is twice that of an only Cr film and three times that of an only Au film. This film structure is easily fabricated and can operate with lasers having different central wavelengths or even white light sources, leading to its applications in many fields, including photoacoustic communications and audio transducers.

Printed Acoustic Sensor for Low Concentration Volatile Organic Compound Monitoring

Printed electronics employing flexible substrate offers prospective features for various applications such as, tactile sensing, energy harvesting, wearable electronics and acoustic wave sensors. In this work, an acoustic FPW (flexural plate wave) sensor is printed on thin and flexible PZT-PDMS (lead zirconate titanate-poly dimethyl siloxane) composite film with silver ink. The prototype FPW resonator has a resonant frequency of 22.65 MHz with an attenuation of -1.552 dBm. Gravimetric mass sensitivity of the sensor was measured by applying PDMS layers in between the input and output interdigital transducers (IDTs). The mass sensitivity was measured to be -7.8 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /g. The sensor is highly responsive to VOCs (volatile organic compounds) with PDMS as a sensing layer. Gas sensitivities with acetic acid and toluene concentrations were measured to be 0.66 and 160.63 kHz/ppm, respectively. The limit of detection for acetic acid and toluene were 10.9 and 0.03 ppm, respectively. Further, the sensor shows good repeatability and response time with both the VOCs. The thermal stability and high piezoelectric charge coefficient of PZT-PDMS composite compared to other piezoelectric composite and polymer substrates are advantageous for the flexible printed sensor. The reported FPW gas sensor shows potential for low concentration measurement of VOCs.

Transparent low-voltage-driven soft actuators with silver nanowires Joule heaters

Transparent soft actuators with silver nanowire Joule heaters embedded in liquid crystal elastomer and PDMS layer was prepared, and it can perform reversible large bending deformation driven by low voltage.

Soft imprint lithography for liquid crystal alignment using a wrinkled UVO-treated PDMS transferring method

Soft imprint lithography for liquid crystal (LC) alignment using a poly(dimethylsiloxane) (PDMS) wrinkled structure formed by UV–ozone (UVO) treatment was investigated in this study. Oxidation of the PDMS surface formed a silica-like outer layer that caused elastic moduli mismatch with the inner PDMS layer, leading to the formation of a wrinkled structure. This wrinkled PDMS was used as a stamp for LC alignment via soft imprint lithography. The wrinkled structure was transferred to the polyimide alignment layer and then LC cells were fabricated using the wrinkled substrates. The pretilt angle and electro-optical properties of the LC cells fabricated in this manner had performance similar to that of LC cells fabricated using the conventional rubbing method.

Fabrication of Glass Micropipette Device Using Reflow Processes and Its Integration With Microfluidic Channels for Patch Clamp Recording of Cell

This paper presents a borosilicate glass micropipette device that has a high-aspect-ratio pore for patch clamp recording applications. The device was fabricated by carrying out glass reflow processes on a silicon substrate. The shape of the micropipette was determined by the width and thickness of the reflowed glass structure, which matches well with the rounded tip of a conventional glass pipette. The diameter of the micropipette pore was first defined by deep reactive ion etching (DRIE) of a silicon pillar, which was positioned at the center of the glass structure. Then, the silicon pillar was removed, and the pore diameter was additionally reduced to the submicron scale by depositing a parylene-C film. The fabricated device was integrated with microfluidic channels for patch clamp recording experiments: microfluidic PDMS layers were assembled on the top and bottom surfaces of the micropipette chip for the medium exchange and the application of negative pressure, respectively. The quality of seal between a cerebral cortex cell of a rat and the glass micropipette was characterized by the amplitude of the current produced by an applied voltage pulse. A negative pressure applied through the bottom microfluidic channel pulled down the cell and increased the seal resistance from 9.82 $\text{M}\Omega $ to 2.06 $\text{G}\Omega $ . This indicates that the gigaseal was successfully formed around the micropipette pore. In addition, the action potentials of the patched cortical neuron were recorded using the fabricated device.

Multi-layer PDMS films having antifouling property for biomedical applications

Poly(dimethylsiloxane) (PDMS) elastomer is now a well-known material for packaging implantable biomedical micro-devices owing to unique bulk properties such as biocompatibility, low toxicity, excellent rheological properties, good flexibility, and mechanical stability. Despite the desirable bulk characteristics, PDMS is generally regarded as a high-flux material for oxygen and water vapor to penetrate compared with other polymeric barrier materials, which is related to the defect-induced penetration through the packaging coating prepared by the traditional deposition techniques. Besides, its hydrophobic nature causes serious fouling problems and limits the practical application of PDMS-based devices. In this work, the performance of silicone thin films as a packaging layer was improved by the fabrication of the roller-casted multiple thin layers to minimize a defect-induced failure. To confer hydrophilicity and cell fouling resistance, high-density and well-defined poly(oligo(ethylene glycol) methacrylate) (POEGMA) brushes were tethered via the surface-initiated atom transfer radical polymerization (SI-ATRP) technique on the roller-casted multiple thin PDMS layers. The characteristics of fabricated substrates were determined by static water contact angle measurement, X-ray photoelectron spectroscopy, and attenuated total reflection-Fourier transform infrared spectroscopy. In vitro cell behavior of POEGMA-grafted PDMS substrates was evaluated to examine cell-fouling resistance.

Single-molecule tracking measurement of PDMS layer during curing process

The curing process of poly(dimethylsiloxane) (PDMS) was microscopically investigated by the single-molecule tracking method based on the diffusion motion of fluorescent dye molecules adding to the PDMS layer stored at a temperature of 308K. The PDMS layer was completely cured at 900 min after adding a curing agent. We compared the time- and ensemble-averaged mean square displacements (MSDs) of the tracked molecules at 90, 510, and 900 min after adding the curing agent into the PDMS layer. The discrepancies were observed between the time- and ensemble-averaged MSDs, indicating weak ergodicity breaking. The spatially averaged diffusion coefficient exhibited a two-step decrease: first step was rapid decrease suggesting the extent of crosslinking, and second step was slow one suggesting the increase of crosslink density. The single-molecule trajectory scale analysis revealed the heterogeneous distribution of the diffusion coefficient. By calculating the heat map from the slope of moment scaling spectrum (MSS) of each single-molecule trajectory, cluster structures were recognized. The spatial correlation of the slope of MSS decreased with the time elapsed. These results suggested the existence of the heterogeneous structure in the PDMS layer during the curing process.

Integrated and finger-actuated microfluidic chip for point-of-care testing of multiple pathogens

The integration of gel-based loop-mediated isothermal amplification (gLAMP) and finger-actuated microfluidic chip (μFAchip) was developed for the simultaneous detection of various different types of bacterial pathogens. The developed μFAchip consisted of three PDMS layers attached together by two adhesive tapes. Multiple chambers in the top PDMS layer were used for sample preparation, and the corresponding chambers in the bottom PDMS layer was used for long-term storage of LAMP reagents without DNA templates. The thin PDMS layer in the middle contained cross-shaped cuts as finger-actuated valves for fluid control. To reduce operation steps on the chip, such as pipetting and manipulation of samples, Whatman CloneSaver card was pre-embedded in the top chambers for on-chip DNA extraction and purification. Upon a simple press on the top layer, the finger-actuated valve was opened up, allowing DNA samples on the top layer flow into the bottom reaction chambers for gLAMP reaction. For POCT applications, on-chip LAMP reaction and imaging were conducted on a miniaturized peltier heater and a portable fluorescence imaging system respectively. Under the optimized condition, multiple pathogens were detected simultaneously with high selectivity and sensitivity (as low as 1.6 cells). The developed μFAchip provided a rapid and easy-to-operate platform for gLAMP-based pathogen detection, with the potential for in-field detection, especially in areas with limited resources.

Properties of polydimethylsiloxane hydrophobic modified duplex microarc oxidation/diamond-like carbon coatings on AZ31B Mg alloy

A reliable, high-performance coating procedure was developed using PDMS to modify a duplex MAO/DLC coating on an AZ31B Mg alloy. First, the duplex MAO/DLC coating was fabricated via a combined MAO and unbalanced magnetron sputter process. Subsequently, a PDMS solution was used to modify the MAO/DLC coating via a conventional dip-coating method. The surface characteristics, bond strength, hardness, tribological behaviour, and corrosion resistance of the coated samples were evaluated via SEM, CA, Raman spectroscopy, friction and wear behaviour, polarisation curve, and NSS tests. The PDMS modification reduced the H IT of MAO/DLC coating from 15.96 to 8.34 GPa; this is ascribed to the penetration of PDMS, which has good rheological properties to form a viscoelastic Si-based organic polymer layer on the MAO/DLC coating. However, the PDMS-modified MAO/DLC coating was denser, hydrophobic, and had higher bond strength compared with MAO- and MAO/DLC-coated samples. Moreover, the PDMS modification reduced the COF and wear rate of the duplex MAO/DLC coating. This indicates that the PDMS improved the tribological behaviour owing to the transferred Si oxide that originated from the Si-O network of the PDMS, as well as the low graphitisation of the DLC layer during sliding. Furthermore, the corrosion current density of the MAO/DLC-coated sample modified by PDMS for 10 min decreased by two order of magnitude compared with that of the MAO/DLC-coated sample but by five orders of magnitude compared with that of the bare substrate. The NSS tests proved that the PDMS layer slowed the corrosion of the Mg alloy under long-term service, enhancing the corrosion protection efficiency. The results are attributed to the high bond strength and lubricant MAO/DLC layer, and the dual role of sealing and hydrophobicity of PDMS. Therefore, PDMS modification is promising for the fabrication of protective materials for Mg alloys that require corrosion and wear resistance.