Smooth Polydimethylsiloxane Research Articles

Dynamic electromechanical characterizations of poly(vinylidene fluoride) based nanocomposite films on ultra‐low modulus polymer substrate

AbstractThis article explores the electromechanical performance of poly(vinylidene fluoride) (PVDF) films with silver nanoplatelets on smooth polydimethylsiloxane (PDMS) substrates. PVDF, a semi‐crystalline polymer, shows piezoelectric properties when processed at low temperatures, making it ideal for energy harvesting and sensors. This research addresses a gap by examining high strain rate and complex electromechanical characteristions of PVDF composites, which are underexplored. Films, fabricated using a non‐vacuum rod coating method, underwent dynamic electromechanical tests (strain rate ~ 2 s−1), including stretching, twisting, combined stretching and twisting, and forced vibrations. Results show the films function up to 17% applied strain with a gage factor of 10.57. In twisting tests, the laminates perform up to 387° in slow twisting (gage factor = 28.34) and 341° in fast twisting (gage factor = 7.65). Combined stretching and twisting tests show performance decreases, with functionality up to 6.24% strain at a twist angle of 330.1°. Vibration tests reveal that increased amplitude reduces performance, with the laminates enduring frequencies between 4.35 and 12.14 Hz. The films also exhibit a linear piezoelectric response, with a maximum open circuit voltage of 37.2 V under an impact load of 1112 N, underscoring the potential of PVDF/Ag nanocomposites for advanced MEMS applications.

In vitro formation and extended culture of highly metabolically active and contractile tissues.

3D cell culture models have gained popularity in recent years as an alternative to animal and 2D cell culture models for pharmaceutical testing and disease modeling. Polydimethylsiloxane (PDMS) is a cost-effective and accessible molding material for 3D cultures; however, routine PDMS molding may not be appropriate for extended culture of contractile and metabolically active tissues. Failures can include loss of culture adhesion to the PDMS mold and limited culture surfaces for nutrient and waste diffusion. In this study, we evaluated PDMS molding materials and surface treatments for highly contractile and metabolically active 3D cell cultures. PDMS functionalized with polydopamine allowed for extended culture duration (14.8 ± 3.97 days) when compared to polyethylamine/glutaraldehyde functionalization (6.94 ± 2.74 days); Additionally, porous PDMS extended culture duration (16.7 ± 3.51 days) compared to smooth PDMS (6.33 ± 2.05 days) after treatment with TGF-β2 to increase culture contraction. Porous PDMS additionally allowed for large (13 mm tall × 8 mm diameter) constructs to be fed by diffusion through the mold, resulting in increased cell density (0.0210 ± 0.0049 mean nuclear fraction) compared to controls (0.0045 ± 0.0016 mean nuclear fraction). As a practical demonstration of the flexibility of porous PDMS, we engineered a vascular bioartificial muscle model (VBAM) and demonstrated extended culture of VBAMs anchored with porous PDMS posts. Using this model, we assessed the effect of feeding frequency on VBAM cellularity. Feeding 3×/week significantly increased nuclear fraction at multiple tissue depths relative to 2×/day. VBAM maturation was similarly improved in 3×/week feeding as measured by nuclear alignment (23.49° ± 3.644) and nuclear aspect ratio (2.274 ± 0.0643) relative to 2x/day (35.93° ± 2.942) and (1.371 ± 0.1127), respectively. The described techniques are designed to be simple and easy to implement with minimal training or expense, improving access to dense and/or metabolically active 3D cell culture models.

Highly strong bio-inspired ZnO/PDMS superhydrophobic surface with drag reduction and antibacterial properties

Maintaining the long-term stability of water repellency and antifouling remains a challenge. This study presents the fabrication of a solid sharkskin-inspired surface exhibiting superhydrophobic and antifouling properties by polydimethylsiloxane (PDMS) and zinc oxide (ZnO) nanostructures through the simple microcasting and hydrothermal methods. The ZnO grown under optimal reaction parameters showed a remarkable contact angle of 151°, signifying the emergence of superhydrophobicity. Furthermore, the ZnO/PDMS sharkskin surface was found to reduce drag by up to 12.2%. Notably, the bacterial adhesion was decreased on the sharkskin-like PDMS surface with ZnO nanostructures by 96.5% compared to smooth PDMS. This resulted from the combined antifouling effects of ZnO photocatalytic property and the microstructure-induced hydrophobicity. Additionally, the ZnO nanostructures demonstrated exceptional mechanical stability and robustness.

Pinning of graphene for conformal wrinkling over a soft corrugated substrate through prestretch-release process

The adhesion of a 2D material to a substrate is facilitated by the van der Waals (vdW) interactions, which is significantly influenced by the roughness and wettability of the substrate. It is challenging to achieve good as well as conformal adhesion of mechanically exfoliated 2D materials to a hydrophobic soft substrate like polydimethylsiloxane (PDMS). In addition, the mechanical folding instabilities are inevitably observed in 2D elastic nanosheets over a smooth PDMS substrate under higher compressions in a prestretch-release process. However, the manipulation of the soft substrate’s surface roughness may provide an essential degree of freedom for tailoring the conformation level and topography of the 2D elastic nanosheets. Herein, we propose a technique to improve the interfacial adhesion of the graphene membrane to a periodically trenched PDMS substrate by suppressing the mechanical folding instabilities in a prestretch-release process. The conformal wrinkling of the graphene membrane, as confirmed through atomic force microscopy (AFM) imaging, is found to result from its pinning into the trenches via snap-through transition. We also show the impact of the substrate’s topography on the buckling behavior of the graphene membrane under the stress loading-unloading cycle by surface-engineering of the PDMS substrate using ion beam irradiation. This study offers fundamental as well as practical insights into the adhesion mechanics of the 2D elastic nanosheets over the corrugated soft substrates under the prestretch-release process. The wrinkled topography of the membrane could be harnessed for flexible, conformal, and tunable electronic devices.

Friction measurement of modified Polydimethylsiloxane(PDMS) surfaces inspired by Malayopython Reticulatus

The lack of limbs on snakes enables its ventral scales to be in almost constant contact with the substrate. Their skin is presumably adapted to generate high and low friction to slither. This frictional characteristics in snakes were hypothesized to be contributed by the be tooth-shaped or denticle-like microstructures found on the snake ventral scales. The frictional properties of the microstructures found on snake ventral scales was studied and its feasibility as an inspiration for surface modifications was observed. This study was carried out to analyze the frictional anisotropy exhibit by the snake ventral scale microstructures and also how it changes the frictional properties of the PDMS surface when the microstructures are replicated on to it. The PDMS embedded-elastomeric stamping method was used in this experiment to replicate the snake ventral scales onto the PDMS. Based on the data collected the microstructures on the snake ventral scales does exhibit frictional anisotropy. The PDMS with replicated snakeskin microstructures displays higher COF compared to PDMS with smooth surface. When sliding on most types of surfaces, the COF of real snakeskin and replicated snakeskin is higher if the surface is semi wet. Whereas for smooth PDMS the COF is lower when the surfaces are semi wet. Generally, from both experiments, when the replicated snakeskin is sliding on the surface in the lateral direction, it is observed that the COF is the lowest followed by the caudal then the rostral direction.

Enhanced Triboelectric Nanogenerator Performance Based on Mechanical Imprinting PDMS Microstructures

AbstractA vertical contact‐separated mode triboelectric nanogenerator (TENG) is fabricated by imprinting the nylon mesh to obtain the polydimethylsiloxane (PDMS) film with micro‐nano structure, and it is used to provide electric energy for the impressed current cathodic protection. The output of PDMS film obtained by 200 mesh nylon mesh imprinting is significantly improved, with an open circuit potential of 1120 V and a charge transfer of 63 nC, which is about twice that of a smooth PDMS film. It also performs well for cathodic protection, and electrochemical test results show that the open circuit potential of the protected metal in artificial seawater can decrease by 275 mV. Experiments show that the output of TENG can make calculators, flame alarms, and other electronic equipment work normally after being stored by capacitors. In addition, this work has the advantages of having simple operation, low equipment demands, and low cost.

Flexible capacitive pressure sensor based on multi-walled carbon nanotubes microstructure electrodes

Flexible pressure sensors have been widely used in wearable devices, medical and health, smart services and other industries. However, the fabrication of sensor with high sensitivity, large sensing range and good stability is still a vital research topic. Herein, a flexible capacitive pressure sensor based on micro-structured electrode is developed, which uses a micro-structured polydimethylsiloxane (PDMS) film embedded with a layer of multi-walled carbon nanotubes as the micro-structured conductive electrode, and a smooth PDMS film as the dielectric layer. The results indicate that the sensor exhibits a strong linear pressure-capacitance relationship. The sensitivity of the sensor can reach 1.3 kPa−1 in the pressure range of 0–100 Pa by optimizing the size of the electrode microstructure. In addition, the sensor exhibits a good repeatability even after 4000 repeated pressing. In addition, we demonstrate that the pressure sensor can be applied to monitor arterial pulse waves and breathing. The sensor is assembled in the form of arrays, which can effectively detect the shape of the measured object, proving that the sensor can be applied in complicated scenarios such as service robot and wearable equipment.

초발수 특성을 이용한 기체투과성 방수 필름 제작 및 특성 평가

In this paper, a gas permeable waterproof film with superhydrophobic characteristics of irregular microstructures and vertical microchannels, is presented. A wet etching technique of aluminum alloys was employed for the preparation of a superhydrophobic surface, and a typical punching technique was used for the fabrication of vertical microchannels. A waterproof film was created via the casting process of polydimethylsiloxane (PDMS). The contact angle of the prepared film was measured as 156°, and the diameter of the vertical microchannel was approximately 100 μm. In the experiment involving maximum liquid entry pressure (LEP) measurement, the LEP of the microtextured PDMS film with 50 vertical microchannels was approximately 16 kPa, whereas the smooth PDMS film could not withstand any pressure. In the long-term reliability test, by using a pressure relief valve of 14 kPa, the fabricated film maintained the water pressure without any leakage.

Frictional effect of spherical convex textured rigid bodies sliding on smooth PDMS

Surface texturing was applied to flexible friction couples to improve their tribological behavior. Spherical convex texture was fabricated on the surface of photosensitive resin by stereolithography (SLA), the friction coefficient between the textured resin sample and smooth polydimethylsiloxane (PDMS) under the conditions of low sliding speed and dry friction was measured using a self-made frictional test bench. It was found that surface texture is capable of reducing friction at low applied normal load compared with the non textured friction couple, as well as increasing friction at high load, in addition, smaller texture radii tend to increase friction. At last, the friction mechanism of the textured flexible friction couple was discussed by establishing a mechanical model.

Optimization of micromilled channels for microfluidic applications using gas-blowing-assisted PDMS coating

Micromilling is a flexible, inexpensive and rapid prototyping technique for polymer microfluidic devices. However, the applications of microfluidic devices fabricated by micromilling have been compromised by their poor surface quality. In this study, we demonstrated a gas-blowing-assisted (GBA) polydimethylsiloxane (PDMS) coating that is used to reduce the surface roughness of micromilled channels, yielding optical grade channel walls while simultaneously offering high flexibility in channel dimensions and morphology by controlling the coating parameters. In this method, a thin layer of PDMS is coated on the engraved substrate, and then a computer numerical control (CNC)-guided gas-blowing is used to selectively remove surplus PDMS prepolymer in channels, which results in a thin residual and smooth PDMS coating on the walls of channels. With this GBA PDMS coating, the channel surface roughness of below 8 nm could be achieved without the need of advanced polishing equipment or procedures. Furthermore, this method has the capability to fabricate non-rectangular microchannels with different shapes in cross-section depending on the process parameters, which benefits microvascular research and tissue engineering.

Preparation of superhydrophobic flexible tubes with water and blood repellency based on template method

Superhydrophobic surfaces have been widely used in biology, medicine, aerospace and other fields due to their special surface wettability. The surface wettability of materials mainly depends on the surface chemical composition and surface morphology. Therefore, the wettability of materials can be effectively controlled by changing the surface chemical composition and surface morphology. In this paper, the hydrophobic templates with different wettability were obtained by controlling the laser etching distance of 6061 aluminium alloy tube surface. The superhydrophobic flexible tubes were further fabricated using prepared 6061 aluminum alloy tubes as the template and polydimethylsiloxane (PDMS) for replica. The contact angles of water and blood could reach 162.8°and 152.1° respectively. By using scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FTIR), it could be seen that there were micron-sized structures and hydrophobic groups on the surface. The free energy on the surface of superhydrophobic PDMS was 70.7% lower than that on smooth PDMS. In addition, the superhydrophobic flexible tube had excellent durability and abrasion resistance, and the prepared surface was also blood repellency. Blood droplets easily passed through the inclined flexible tube without contaminating the tube. And the superhydrophobic flexible tubes could be used in various fields requiring productivity extensively, such as medical catheters.

In-situ icing and water condensation study on different topographical surfaces

Icephobicity is intrinsically affected by rough asperities and the surface voids provide anchoring points for the ice. The anchor of ice is likely to form on the surface under high humidity conditions. In-situ water condensation and icing observation were conducted to understand water condensation and ice retracting patterns in controlled humidity, pressure and temperature conditions. It was observed that water micro-condensation and icing occurred on rougher surfaces and the water droplets condensed along the surface cracks of the superhydrophobic polydimethylsiloxane (PDMS) based nanocomposite coatings. Further analysis revealed that ice anchoring was present on both aluminum and superhydrophobic coating surface, but it was more severe and intensified on the as-received aluminum substrates. No water condensation or subsequent icing was found on smooth PDMS hydrophobic surfaces due to the incapacity of the smooth surfaces to anchor water drops. It is the first time to validate ice anchoring over retracting ice on different wettability surfaces from in-situ icing observation. Ice adhesion strengths were also measured on the studied surfaces and the results indicated a strong linkage between centrifugal shearing of ice and anchoring mechanism due to surface rough voids, and there was no clear relevancy between ice adhesion strength and the surface wettability or hydrophobicity.

Research on the selective adhesion characteristics of polydimethylsiloxane layer

Polydimethylsiloxane (PDMS) is a widely used inexpensive, non-toxic material which has many advantages. But it is generally considered that PDMS does not adhere to the other substrates without the special treatments due to its low surface energy. However, in this paper, it is the first time that we found that the PDMS adhered on the silicon dioxide substrate to form an adhesive layer only by the routine cast molding process. The mechanism of the PDMS adhesion on the silicon dioxide substrate during the process was illustrated in detail. The smooth, thin, transparent, hydrophobic and selective PDMS adhesion layer can be used as a functional coating to improve the special performances of the micro/nano devices. Finally, as an example, a facile approach is proposed to realize the superhydrophobic surfaces by combining the SiO2 microstructure with the PDMS adhesion layer.

Dynamics of a flexible superhydrophobic surface during a drop impact

In this study, coupled dynamic responses of flexible superhydrophobic surfaces during a drop impact were investigated with position sensing and high-speed imaging. A smooth polydimethylsiloxane surface was spray coated with commercially available superhydrophobic paint particles. The influence of initial and subsequent impacts of a water droplet on the surface dynamics was studied at various natural frequencies of the surface (50 < fs < 230 Hz) and Weber numbers (2 < We < 90). We discovered that the flexible superhydrophobic surface was deflected twice during contact of the droplet by an impact force of the droplet as well as its reaction force during recoil. The magnitude of the droplet reaction force was estimated to be comparable to the droplet impact force. As the Weber number increased, however, the influence of the droplet reaction force on the surface displacement was attenuated because of the instability of the droplet rim. The contact time of the droplet and surface dynamics were found to be dependent on the phase of the surface. The contact time was reduced as much as 7% when a completion of the droplet spreading matched to the upward motion of the surface. One of the two local minima of the surface position observed during the contact of the droplet was diminished by matching the instance of the droplet reaction force to the downward motion of the surface. This study provides new insight into the effect of the droplet reaction force on dynamics of flexible superhydrophobic surfaces.

Effects of internal concentration polarization and membrane roughness on phenol removal in extractive membrane bioreactor

Recent studies have proved the advantages of novel composite membranes in the extractive membrane bioreactor (EMBR) for recalcitrant organic wastewater treatment. However, more systematic research into membrane properties and mass transfer effects are required. This study investigates the role of internal concentration polarization (ICP), including concentrated and diluted ICP, in an aqueous-aqueous extractive process, and the coupled effects of membrane roughness and hydrodynamic conditions on membrane performance in both cross-flow EMBR (CF-EMBR) and submerged EMBR (S-EMBR) processes. To study these factors, a nanofibrous composite membrane with a four-tiered structure, consisting of a dense polydimethylsiloxane (PDMS) selective layer, a polyvinylidene fluoride (PVDF) nanofibrous sublayer, a non-woven mechanical support and a rough micro/nano-beaded layer, has been developed for the EMBR by electrospinning and spray-coating.A diluted ICP, which occurred when the selective layer faces receiving water (SL-Rw), was less severe than a concentrated ICP in the selective layer facing feed (SL-F) orientation. It resulted in higher overall membrane mass transfer coefficients (k0's) in the SL-Rw mode during the aqueous-aqueous extractive tests. In addition, less biofilm was observed on the smooth PDMS surface after 14-days CF-EMBR and S-EMBR operations in the selective layer facing biomedium (SL-Rbio) mode. In contrast, in the SL-F mode during EMBR operations, the ridges and valleys on the membrane surface were able to provide a more favourable micro-environment for microorganisms and protect them from external stresses. The mature micro-colonies that developed in the SL-F mode clogged the membrane support and enhanced concentrated ICP, resulting in a significant reduction of k0's by more than 58%. Moreover, as the shear force on the membrane surface due to up-flow of air bubbles in the S-EMBR could mitigate the biofilm attachment, the most effective biofilm control strategy found in this study was to operate the nanofibrous composite membrane in the S-EMBR configuration with a smooth selective layer facing the biomedium. This effectively decreased the amounts of protein by 86%, polysaccharides by 88% and total suspended solids (TSS) by 89% in the biofilms on membrane surface, and achieved the highest stable k0 of 7.0 × 10−7 m/s.

Aqueous Lubrication, Structure and Rheological Properties of Whey Protein Microgel Particles.

Aqueous lubrication has emerged as an active research area in recent years due to its prevalence in nature in biotribological contacts and its enormous technological soft-matter applications. In this study, we designed aqueous dispersions of biocompatible whey-protein microgel particles (WPM) (10-80 vol %) cross-linked via disulfide bonding and focused on understanding their rheological, structural and biotribological properties (smooth polydimethylsiloxane (PDMS) contacts, Ra < 50 nm, ball-on-disk set up). The WPM particles (Dh = 380 nm) displayed shear-thinning behavior and good lubricating performance in the plateau boundary as well as the mixed lubrication regimes. The WPM particles facilitated lubrication between bare hydrophobic PDMS surfaces (water contact angle 108°), leading to a 10-fold reduction in boundary friction force with increased volume fraction (ϕ ≥ 65%), largely attributed to the close packing-mediated layer of particles between the asperity contacts acting as "true surface-separators", hydrophobic moieties of WPM binding to the nonpolar surfaces, and particles employing a rolling mechanism analogous to "ball bearings", the latter supported by negligible change in size and microstructure of the WPM particles after tribology. An ultralow boundary friction coefficient, μ ≤ 0.03 was achieved using WPM between O2 plasma-treated hydrophilic PDMS contacts coated with bovine submaxillary mucin (water contact angle 47°), and electron micrographs revealed that the WPM particles spread effectively as a layer of particles even at low ϕ∼ 10%, forming a lubricating load-bearing film that prevented the two surfaces from true adhesive contact. However, above an optimum volume fraction, μ increased in HL+BSM surfaces due to the interpenetration of particles that possibly impeded effective rolling, explaining the slight increase in friction. These effects are reflected in the highly shear thinning nature of the WPM dispersions themselves plus the tendency for the apparent viscosity to fall as dispersions are forced to very high volume fractions. The present work demonstrates a novel approach for providing ultralow friction in soft polymeric surfaces using proteinaceous microgel particles that satisfy both load bearing and kinematic requirements. These findings hold great potential for designing biocompatible particles for aqueous lubrication in numerous soft matter applications.

Fabricating smooth PDMS microfluidic channels from low-resolution 3D printed molds using an omniphobic lubricant-infused coating

The advent of 3D printing has allowed for rapid bench-top fabrication of molds for casting polydimethylsiloxane (PDMS) chips, a widely-used polymer in prototyping microfluidic devices. While fabricating PDMS devices from 3D printed molds is fast and cost-effective, creating smooth surface topology is highly dependent on the printer's quality. To produce smooth PDMS channels from these molds, we propose a novel technique in which a lubricant is tethered to the surface of a 3D printed mold, which results in a smooth interface for casting PDMS. Fabricating the omniphobic-lubricant-infused molds (OLIMs) was accomplished by coating the mold with a fluorinated-silane to produce a high affinity for the lubricant, which tethers it to the mold. PDMS devices cast onto OLIMs produced significantly smoother topology and can be further utilized to fabricate smooth-channeled PDMS devices. Using this method, we reduced the surface roughness of PDMS microfluidic channels from 2 to 0.2 μm (10-fold decrease), as well as demonstrated proper operation of the fabricated devices with superior optical properties compared to the rough devices. Furthermore, a COMSOL simulation was performed to investigate how the distinct surface topographies compare regarding their volumetric velocity profile and the shear rate produced. Simulation results showed that, near the channel's surface, variations in flow regime and shear stress is significantly reduced for the microfluidic channels cast on OLIM compared to the ones cast on uncoated 3D printed molds. The proposed fabrication method produces high surface-quality microfluidic devices, comparable to the ones cast on photolithographically fabricated molds while eliminating its costly and time-consuming fabrication process.

Water and Blood Repellent Flexible Tubes

A top-down scalable method to produce flexible water and blood repellent tubes is introduced. The method is based on replication of overhanging nanostructures from an aluminum tube template to polydimethylsiloxane (PDMS) via atomic layer deposition (ALD) assisted sacrificial etching. The nanostructured PDMS/titania tubes are superhydrophobic with water contact angles 163 ± 1° (advancing) and 157 ± 1° (receding) without any further coating. Droplets are able to slide through a 4 mm (inner diameter) tube with low sliding angles of less than 10° for a 35 µL droplet. The superhydrophobic tube shows up to 5,000 times increase in acceleration of a sliding droplet compared to a control tube depending on the inclination angle. Compared to a free falling droplet, the superhydrophobic tube reduced the acceleration by only 38.55%, as compared to a 99.99% reduction for a control tube. The superhydrophobic tubes are blood repellent. Blood droplets (35 µL) roll through the tubes at 15° sliding angles without leaving a bloodstain. The tube surface is resistant to adhesion of activated platelets unlike planar control titania and smooth PDMS surfaces.

Microgrooved topographical surface directs tenogenic lineage specific differentiation of mouse tendon derived stem cells

Tendon derived stem cells (TDSCs) are the endogenous cell source for tenocyte turnover and tendon functional maintenance. They are also the important cell source for tendon engineering and regeneration. In addition, TDSCs also play an important role in tendinopathy via their non-tenogenic lineage differentiation. It has been well demonstrated that cell shape could determine mesenchymal stem cell (MSC) lineage differentiation. In this study, a parallel microgrooved polydimethylsiloxane (PDMS) membrane (10 µm groove width and 3 µm depth) was employed to investigate the role of cell elongation via this particular topographic surface in directing murine TDSC (mTDSC) lineage differentiation. The results showed that elongated mTDSCs exhibited significantly enhanced the gene expression of tenogenic markers when compared to the spread cells that grew on smooth PDMS membrane including tenomodulin, scleraxis, collagens I, III, and VI, decorin and tenascin (p < 0.05). Meanwhile, stemness related genes such as Nanog, Sox2 and Oct4 were significantly inhibited for their expression in elongated mTDSCs (p < 0.05). When under tri-lineage induced differentiation, cell elongation significantly inhibited mTDSC differentiation towards chondrogenic and adipogenic lineages (p < 0.05). Furthermore, cell elongation could significantly inhibit mTDSC osteogenic lineage differentiation (p < 0.05) induced by BMP-2, a tendinopathy mimicking stimulant. In conclusion, simulation of native tendon structure via using parallel microgrooved topography can promote mTDSC differentiation specifically towards tenogenic lineage and prevent non-tenogenic lineage differentiation, providing an insight into the design of tendon regenerative materials.

Multiscale crack initiator promoted super-low ice adhesion surfaces.

Preventing icing on exposed surfaces is important for life and technology. While suppressing ice nucleation by surface structuring and local confinement is highly desirable and yet to be achieved, a realistic roadmap of icephobicity is to live with ice, but with lowest possible ice adhesion. According to fracture mechanics, the key to lower ice adhesion is to maximize crack driving forces at the ice-substrate interface. Herein, we present a novel integrated macro-crack initiator mechanism combining nano-crack and micro-crack initiators, and demonstrate a new approach to designing super-low ice adhesion surfaces by introducing sub-structures into smooth polydimethylsiloxane coatings. Our design promotes the initiation of macro-cracks and enables the reduction of ice adhesion by at least ∼50% regardless of the curing temperature, weight ratio and size of internal holes, reaching a lowest ice adhesion of 5.7 kPa. The multiscale crack initiator mechanisms provide an unprecedented and versatile strategy towards designing super-low ice adhesion surfaces.