Thermoplastic Polyurethane Foam Research Articles

The Application of Box-Behnken Design for Investigating the Supercritical CO2 Foaming Process: A Case Study of Thermoplastic Polyurethane 85A.

Thermoplastic polyurethane (TPU) is a versatile polymer with unique characteristics such as flexibility, rigidity, elasticity, and adjustable properties by controlling its soft and hard segments. To properly design and understand the TPU foaming process through supercritical CO2, a design of experiments approach, the Box-Behnken design (BBD) was adopted using commercial TPU 85A as the model compound. The effect of saturation pressure, saturation temperature, and immersion time on the mean pore size and expansion ratio were investigated. The design space for the production of TPU foam was shown, and the significance of process parameters was confirmed using the analysis of variance (ANOVA). In addition, extrapolation foaming experiments were designed and validated the feasibility of the response surface model developed via BBD. It was found that the pore size of TPU 85A foam could be controlled within 13 to 60 μm, and a stable expansion ratio could be designed up to six.

A novel semi-continuous preparation mode of ultra-low density thermoplastic polyurethane foam

The production of elastomer foam commonly faces challenges like low production efficiency, limited controllability, uneven foaming, and inherent shrinkage characteristics, especially in manufacturing thick foam sheets. Addressing these, this study introduces innovative “semi-continuous foaming with ultra-low-pressure” (SFU) strategy that integrates low-temperature gas-locking, conduction-microwave heating, and N2-assisted gas-exchange, aimed at optimizing the entire process of TPU foam production, from manufacturing and storage to post-processing. The low-temperature gas-locking scheme realizes semi-continuous preparation of elastomer foam; the conduction-microwave heating scheme significantly improves the heating speed and uniformity; and the N2-assisted gas exchange scheme prevents elastomer foam shrinkage, facilitating the creation of high expansion ratio foam. This process offers the flexibility to adjust initial cell sizes (5–30 μm after shrinkage) and expansion ratios (1–24 times) by manipulating parameters such as microwave radiation time, power, and saturation time. Furthermore, the foam was prepared under ultra-low pressure (<7 MPa), resulting in a final expansion exceeding 14.2 times TPU thick sheet (5 mm thickness before foaming) foam with excellent resilience (energy loss coefficient ∼ 10 % and ball resilience ∼ 68.8 %). This study explores the mechanism by which TPU can self-absorb during microwave heating and extends this process to TPU materials with varying thicknesses (16.5 mm thickness before foaming) and chain compositions, as well as different types of elastomeric materials or materials with elastomer-like properties (e.g., PBAT, etc.). The SFU strategy not only significantly reduces energy and gas consumption but also steers the technological advancement of foam production towards a greener and more sustainable future.

Thermoplastic polyurethane foams derived from cellulose nanofibril/carbon nanotube/(Fe/C) aerogels for efficient electromagnetic interference shielding

The electromagnetic interference (EMI) shielding performance of a material can be enhanced by combining carbon and magnetic components to make the material simultaneously conductive and magnetic. In this work, a series of cellulose nanofibril (CNF)/carbon nanotube (CNT)/(Fe/C)/thermoplastic polyurethane (TPU) foams are fabricated by preforming CNF/CNT/(Fe/C) aerogels followed by combing TPU to improve the mechanical property, where Fe/C is derived from Prussian blue (PB, Fe4[Fe(CN)6]3) after pyrolysis. Consequently, the obtained aerogels and foams display electrical conductivity and magnetism. The CNF/CNT/(Fe/C)/TPU foam reaches a high EMI shielding effectiveness value of 42.2 dB at a thickness of 2 mm when the mass ratio of PB and CNT is 5:1 and the pyrolysis temperature is 650 ℃. Furthermore, the CNF/CNT/(Fe/C)/TPU foam exhibits compression resilience and hydrophobicity. This study is expected to provide a feasible strategy to acquire absorption-dominated EMI shielding materials by imparting conductivity, magnetism and porous structures to the material.

Highly Breathable, Stretchable, and Tailorable TPU Foam for Flexible Gas Sensors.

Continuous real-time monitoring of air quality is of great significance in the realms of environmental monitoring, personal safety, and healthcare. Recently, flexible gas sensors have gained great popularity for their potential to be integrated into various smart wearable electronics and display devices. However, the development of gas sensors with superior sensitivity, breathability, and stretchability remains a challenge. Here, a new high porosity thermoplastic polyurethane (HP-TPU) foam was reported for gas sensors, which exhibited large three-dimensional network structures and excellent mechanical properties. The HP-TPU foam was achieved by using a simple steam-induced method, which was suitable for mass production. The unique structure endowed this foam with 77.5% porosity, 260% strain ability, and 0.45 MPa Young's modulus, which improved 35, 31, and 80%, respectively, compared to previously reported traditional TPU foam (T-TPU) prepared by the drying method. In addition, the foam presented high gas permeability (312 g/m-2, 24 h) and excellent stability, and it remained undamaged even after 2000 cycles at 70% strain. The sensing material was coated on a PET flexible interdigital electrode and sandwiched between two HP-TPU foam layers for a gas sensitivity test. Due to the easy diffusion of gas between the pores and contact with the sensing materials, the HP-TPU foam exhibited a significant reduction of 85% in average response time and 46% in average recovery time, compared to the T-TPU foam. A wearable sensing device, comprising sensing, data processing, and wireless transmission modules, was successfully developed to enable outdoor testing and achieved a detection range at the ppb level. Finally, the cytotoxicity test results confirmed that this flexible gas sensor did not harm human health. These results proved that this HP-TPU foam was an ideal matrix for the flexible gas sensor, exhibiting great application potential in the fields of seamless human-machine integration.

A new microcellular foaming strategy to develop structure-gradient thermoplastic polyurethane foams with enhanced elasticity

Functionally graded polymer foams are advanced materials that exhibit great potential for applications in energy absorption, electromagnetic interference shielding, and high-elasticity due to the graded cellular structure for mechanical performance and functional properties enhancements. However, producing polymer foams with tailored gradient structures remains a significant challenge. Herein, a new microcellular foaming strategy with two-step adsorptions was developed to prepare thermoplastic polyurethane (TPU) foams with gradient cellular structures. The TPU samples were saturated with low-pressure CO2 in the first sorption stage and partially saturated with high-pressure CO2 in the second sorption stage. By regulating CO2 pressure in the first stage and adsorption duration in the second stage, TPU samples with gradient CO2 concentrations were achieved, thereby leading to structure-gradient TPU foams. Finally, a prospective microcellular-macrocellular gradient foam with a cell size range of 30 μm to 400 μm was successfully prepared. The energy loss coefficient of structure-gradient TPU foam can be reduced by 21.5% compared to that of the foam with uniform cellular structure. Structure-gradient TPU foams show significantly enhanced mechanical performance and elasticity, and the underlying mechanism was clarified. The super-elastic TPU foams with tailored gradient structures hold significant promise for broaden applications requiring lightweight, flexibility, and elasticity.

Investigating the role and impact of N2 as a blowing agent in the fabrication of thermoplastic polyurethane foams

Fabricating low-density elastomeric foams with a homogenous cell structure has been challenging because of foam shrinkage. The low modulus of the elastomers and the high diffusivity of blowing agents lead to foam shrinkage and poor surface quality. Using N2 as a physical blowing agent (PBA) is an eco-friendly foaming method to overcome foam shrinkage. In this study, PTMEG-MDI/BD-based TPU with a hardness of 85A, 90A, and 95A were foamed using N2. Nitrogen as a blowing agent created a homogeneous cell structure with an expansion ratio of more than five times, an average cell size of less than 25 μm, and a cell density of more than 109 cells/cm3. The shrinkage ratio and cellular morphology of CO2- and N2-blown TPU foam were compared at their maximum expansion ratio. At the maximum expansion ratio, the N2-blown foams exhibited a fine cell structure with a shrinkage ratio of less than 4%. However, the CO2-blown TPU foam showed a shrinkage ratio of 12.7% with significant cracks in the sample. The results demonstrate that using N2 as a blowing agent can achieve an expansion ratio similar to that of CO2-blown foam, and the shrinkage problems of elastomeric foams can be significantly eliminated, which may help to maintain the physical properties of the foam.

Superhydrophobic Thermoplastic Polyurethane Foam Fabricated by Phase Separation and Silica Coating for Oil-Water Separation.

Oil spills and the presence of oily wastewater have resulted in substantial ecological damage. Superhydrophobic polymer foam with selectivity and adsorption capacity is a promising candidate for efficient oil-water separation. In this study, a method that combines phase separation and silica coating to produce superhydrophobic thermoplastic polyurethane (TPU) foam is proposed. The TPU foam demonstrates superhydrophobicity with a water contact angle of 155.62°, and exhibits a maximum saturated adsorption capacity of 54.11gg-1 . Furthermore, the foam can be utilized as a filter for oil-water separation, maintaining its filtration efficiency (41.2m3 m2 h-1 ) even after ten filtration cycles.

High-elastic and strong hexamethylene diisocyanate (HDI)-based thermoplastic polyurethane foams derived by microcellular foaming with co-blowing agents

Thermoplastic polyurethane (TPU) foams have exhibited promising prospect in many industries such as automobile, sportswear and packaging, due to their outstanding mechanical properties. However, the application of TPU foams prepared by microcellular foaming with CO2 as blowing agents is still limited, due to the serious shrinkage after foaming. Herein, in this study microcellular foaming with mixed CO2 and N2 as co-blowing agents was used to control the shrinking behavior of hexamethylene diisocyanate (HDI)-based TPU foams, and further, the effects of shrinkage, expansion ratio, and cell size on the mechanical properties of TPU foams were decoupled. The results show that the stretching degree of the molecular chain and the solubility of co-blowing agents play a vital role in stabilizing TPU foams. Foams with an expansion ratio of up to 16-fold can be prepared with both pure CO2 and co-blowing agents. The shrinkage ratio of TPU foams prepared with co-blowing agents is 6.3 %, while that of foams prepared with pure CO2 is 37.8 %. Moreover, it is also found that the mechanical properties of TPU foams with a smaller shrinkage ratio are much higher than those with a larger initial expansion ratio and a similar final expansion ratio.

Highly Ordered Thermoplastic Polyurethane/Aramid Nanofiber Conductive Foams Modulated by Kevlar Polyanion for Piezoresistive Sensing and Electromagnetic Interference Shielding

HighlightsKevlar polyanionic chains induced the formation of highly ordered porous thermoplastic polyurethane foams with adjustable pore sizes.A tiny amount of Ti3C2Tx MXene was performed as reducing agent for the electroless deposition of copper nanoparticles.The conductive foam reinforced by aramid nanofibers exhibited excellent piezoresistive sensing and electromagnetic interference shielding performance.

Asymmetric magnetic-electric dual-functional composite foams for ultra-efficient electromagnetic interference shielding with unprecedented low reflection

• Magnetic-electric dual-functional network is constructed in TPU by Fe 3 O 4 @rGO and CNT via scCO 2 foaming. • TPU/CNT/Fe 3 O 4 @rGO composite foam exhibits high EM wave absorption property with an RL min of -46.8 dB. • EMI shielding and EM wave absorption are further improved by introducing an Ag reflection layer. • Asymmetric TPU/CNT/Fe 3 O 4 @rGO/Ag composites possess a high EMI SE of 89.2 dB and the lowest reflection of 0.001. Asymmetric composite foams comprised of iron oxide decorated reduced graphene oxide (Fe 3 O 4 @rGO)/carbon nanotube (CNT)/thermoplastic polyurethane (TPU) foams and a silver layer were developed by vacuum-assisted hot-pressing and supercritical carbon dioxide (scCO 2 ) foaming. The magnetic-electric dual-functional network constructed by Fe 3 O 4 @rGO and CNT nanofillers rendered the foam excellent impedance matching and wave attenuation capability, achieving -46.8 dB reflection loss at ∼2 mm sample thickness. With the reflective silver layer, the asymmetric composite foam realized a unique “low reflection-absorption-reflection-reabsorption” EM wave depletion mechanism and reached preeminent total shielding effectiveness (SE T ) of 89.2-103.5 dB with a reflection shielding effectiveness (SE R ) of 0.24-0.83 dB. The optimized composite foam achieved a low reflectivity (R) of 0.05 (Average value) and a minimum value of 0.001, which holds the lowest record among EMI shielding materials with comparable SE. This work provides new insights into the design of high-efficiency shielding materials with ultra-low reflection features for cutting-edge EMI shielding applications.

Enhanced foaming ability of thermoplastic polyurethane by crystallization during mold-opening foam injection molding with supercritical N2 as blowing agents

This study provides an insight into the foaming of thermoplastic polyurethane (TPU), which was improved by the crystallization of hard segment domains. This study investigated the effects of packing time in the mold-opening foam injection molding (MOFIM) technology on the crystallization behavior of hard segments in TPU and the cell morphology of TPU foams. It was observed that the prolongation of the packing time, corresponding to a longer crystallization time before foaming, induced an increased crystallinity in the injection-molded TPU solids and foams due to the crystals becoming more close-packed. The enhancement of the foamability of TPU was attributed not only to the increased crystallinity of hard segments, but also to the broader distribution of crystals at the same crystallinity. Furthermore, TPU foams with greater hardness have smaller cell size, higher cell density, and narrower distribution in cell size owing to their higher viscosity and storage modulus than those with lower hardness prepared under the same conditions.

A dynamic supercritical carbon dioxide foaming method for fabricating wrinkled surface to enhance triboelectric nanogenerator performance

AbstractTriboelectric nanogenerator (TENG) is a promising energy harvester to overcome the energy depletion issue. The surface structure has been considered as an effective way to enhance the triboelectric performance. Herein, a dynamic supercritical carbon dioxide (scCO2) foaming method, which introduced a scCO2 flow field during scCO2 saturation, was proposed to fabricate thermoplastic polyurethane (TPU) foams with surface wrinkly structures. The size of the surface wrinkles could be regulated in the range of 1.8–10 μm by varying the foaming pressure. The surface wrinkled TPU film with wrinkle wave length of 2.4 μm demonstrated an excellent enhancement in output voltage (130%), current (180%), and maximum transfer charge (130%) when paired with surface structured polydimethylsiloxane film in a TENG. Due to the excellent durability and flexibility of the composing materials, the developed TENG showed outstanding stability in long‐term continuous operation. With a high power density of 0.5 W/m2 achieved on a 107 Ω external load, the flexible TENG could be used to charge capacitors, power light‐emitting‐diodes, and served as a self‐powered sensor to detect various human movement behaviors. This work provides a new path for the fabrication of surface wrinkled films for the sustainable development of high performance TENGs.

Corrugated thermoplastic polyurethane foams with high mechanical strength fabricated by integrating fused filament fabrication and microcellular foaming using supercritical CO2

Thermoplastic polyurethane (TPU) has been widely implemented in many fields due to its good elasticity. Microcellular foaming not only can achieve weight reduction, but also can enhance the elasticity of TPU products. However, the enhancement of elasticity by foaming is limited, while the introduction of corrugated structures can significantly improve the elasticity of TPU foams. Considering the difficulties to produce TPU parts with corrugated structures for conventional processes, fused filament fabrication (FFF) combined with microcellular foaming was developed to fabricate TPU foams with high elasticity. An FFF 3D printer was used to prepare solid TPU samples with corrugated structures, and microcellular foaming was used to fabricate foamed TPU samples. As expected, the corrugated structures have been successfully and precisely preserved in the obtained TPU foams, and further, the TPU foams have expansion ratio of more than 7 and cell density of higher than 1012 cells/cm3. Thanks to the corrugated structures and refined cellular morphology, the 7.09 expanded TPU foams exhibited outstanding compressive properties with an energy loss coefficient of 28% and a maximum stress of higher than 0.25 MPa. It is further found that introducing the corrugated structures or enlarging cell sizes could improve the elasticity and buffering performance of TPU foams.

Research on the cyclic compression performance of polycarbonate-based thermoplastic polyurethane foams prepared by microcellular foaming

Polycarbonate-based thermoplastic polyurethane (TPU) is an advanced thermoplastic elastomer that has excellent yellowing, oxidation and corrosion resistances, as well as outstanding mechanical properties. Polycarbonate-based TPU foams have potentially important applications in sport goods, biomedical, and chip polishing fields. In this study, two microcellular foaming strategies including Heating-Foaming (H-foaming) and Cooling-Foaming (C-foaming) with carbon dioxide as blowing agents were proposed to prepare structure-tunable polycarbonate-based TPU foams. Firstly, TPU foams with similar cellular morphology were prepared by H-Foaming and C-Foaming, and they were used to explore the effect of foaming strategy on the cyclic compression properties of the TPU foam. Secondly, TPU foams with the same expansion ratio but with different cell sizes were prepared by H-Foaming, which were further used to explore the effect of cell sizes on the cyclic compression properties of the TPU foam. Thirdly, TPU foams with similar cell size but with different expansion ratios were prepared, and they were used to explore the dependences of the cyclic compression properties on the expansion ratio of TPU foams. It was found that the compression strength of the TPU foam prepared by C-Foaming can be enhanced by more than 15%, in comparing with that of the TPU foam prepared by H-Foaming. Furthermore, it was demonstrated that the expansion ratio of TPU foam is the key structural factor in determining its compression strength. The compression strength reduced from 5.91 to 0.17 MPa with the expansion ratio increasing from 0 to 7.2. Reducing cell size leads to enhanced compression strength but deteriorated compression resilience. Increasing expansion ratio will firstly deteriorate and then benefit the compression resilience.

Low-energy-consumption fabrication of porous TPU/graphene composites for high-performance microwave absorption and the influence of Fe3O4 incorporation

Fabrication of lightweight, thin thickness, broad bandwidth, strong absorption, and lower filler loading materials are of great interest for microwave absorption. Herein, porous thermoplastic polyurethane (TPU) /graphene composites were successfully prepared via a facile vapor induced phase separation (VIPS) technique. Compared with TPU foam, the introduction of graphene endows the composites favorable microwave absorption ability. The optimized composite foam with 3 wt% graphene (TPU/G-3) exhibits extraordinary wave attenuation capacity with a minimum reflection loss (RL min ) value of − 51.86 dB and effective absorption bandwidth (EAB) of 4.28 dB (12.6–17.0 GHz) at the thickness of 3.1 mm. Microwave attenuation mechanism indicates that the remarkable microwave absorption ability derives from conduction loss, dipole polarization loss, interfacial polarization loss as well as multiple scattering. Incorporating the same amount of Fe 3 O 4 as graphene to TPU/G-3 endows the composites with the RL min of − 58.96 dB, which is slightly better than TPU/G-3 due to more favorable impedance matching. However, the matching thickness becomes much higher to about 8.0 mm, which is mainly attributed to bigger pores caused by Fe 3 O 4 . Moreover, the VIPS strategy provides insight into the fabrication of facile and lightweight polymer-based porous electromagnetic absorption materials. • Vapor induced phase separation method for preparation of TPU-based porous composites. • Graphene facilitates heterogeneous nucleation for smaller pores than TPU foam. • Graphene content of 3 wt% endows composite favorable microwave absorbing performance. • Fe 3 O 4 influences the process of vapor induced phase separation with bigger pores. • Fe 3 O 4 improves the reflection loss but increases matching thickness due to big pores.

Structure-gradient thermoplastic polyurethane foams with enhanced resilience derived by microcellular foaming

Polymer foams with gradient cellular structure show superior mechanical and physical properties, while developing polymer foams with tailored gradient-structures is still challenging. Herein, an environmentally-friendly foaming process with CO2 as blowing agents was developed for fabricating structure-gradient thermoplastic polyurethane (TPU) foams. In the unique microcellular foaming process, a two-step sorption procedure with a low CO2 pressure at the first stage and a high CO2 pressure at the second stage was used to generate gradient CO2 concentration in the solid TPU samples, which results in gradient cellular morphology in TPU foams. By varying the second sorption time, TPU foams with various gradient cellular morphology were prepared. Interestingly, the gradient cellular morphology helped to increase compression strength by 71.4% and modulus by 113.8%, to enhance resilience with a 24.7% reduction in energy loss coefficient and a rebound coefficient of 61.4%, and also to benefit shape-recovery after long compression deformation.

Flexible, conductive, and anisotropic thermoplastic polyurethane/polydopamine /MXene foam for piezoresistive sensors and motion monitoring

It is a challenge to manufacture pressure sensing materials with flexibility, high sensitivity, wide detection range for the development of intelligent electronic products. Herein, a pressure sensor based on thermoplastic polyurethane (TPU)/polydopamine (PDA)/MXene conductive composite foam (TPMF) was prepared by a combination of directional freezing and dip-coating methods. The compressive strength of anisotropic TPU foam (TF) in the vertical direction is increased by 48.1% compared with isotropic foam. Besides, the conductive foam (0.25 S/m) with an MXene content of 3.45 wt% exhibits low density (105.5 mg/cm3), high porosity (91.2%) and good resistance response behavior. The sensor based on TPMF exhibits excellent flexibility, fast response times (∼40 ms), and good durability over 5000 cycles. Furthermore, the composite foam has excellent recognition ability for different compressive strain amplitudes (up to 80%) and a wide stress range (10 Pa-122.5 kPa), as well as a high gauge factor (GF) up to 2.36 in the strain range of 2.5%-20%. The sensor has shown application potential in many fields, including voice recognition, health monitoring, motion monitoring, and artificial electronic skin.

Supercritical CO2 foaming and shrinkage resistance of thermoplastic polyurethane/modified magnesium borate whisker composite

Thermoplastic polyurethane (TPU) foam is eco-friendly prepared with supercritical carbon dioxide (CO2) as a blowing agent. Magnesium borate whisker (Mg2B2O5) modified by borate ester coupling agent (BE) (BE-Mg2B2O5) was introduced into TPU to modulate cell nucleation, bubble growth and foam stabilization depending on the intercalation structure of Mg2B2O5, entanglement effect of BE and increased physical crosslinking density. The modulation of Mg2B2O5 on the hard segment crystallization promoted hard segment’s (HS) microstructure, i.e., physical crosslinking density. The addition of BE-Mg2B2O5 enhanced the rheological properties, maximum tensile strength and elongation at break of TPU composites. Excellent mechanical property and strain-hardening behavior of TPU composites improved the foamability of TPU composites. Mg2B2O5 and entanglement points acted as heterogeneous nucleation sites to momentously increase cell density and reduce bubble size. Intercalation structure of Mg2B2O5, entanglement effect of BE and high physical crosslinking density effectively limited the TPU relaxation and memory recovery. BE-Mg2B2O5 around the cell wall acted as a barrier to slow down the diffusion rate of CO2 from inside the bubble to outside. The dual action synergistically reduced the shrinkage of TPU foam.

Green fabrication of double-sided self-supporting triboelectric nanogenerator with high durability for energy harvesting and self-powered sensing

The first double-sided self-supporting triboelectric nanogenerator (DS-TENG) with high durability and output performance is developed. A sustainable and scalable supercritical carbon dioxide (scCO2) foaming technique is used to fabric porous composite thermoplastic polyurethane (TPU) foams with regular bumps and valleys by embedding a stainless steel mesh (SSM) inside. When packaged using two silicone rubber films, the DS-TENG realizes simultaneous utilization of both sides of the composite foam and effectively prevents the SSM electrode from erosion, which significantly enhances the output performance and durability while maintaining high flexibility. The working mechanism of the DS-TENG is elaborated by manipulating the structure of the composite foam via changing the mesh grid and the foaming conditions. Attributing to the wear resistance of the comprising materials and compact device configuration, the DS-TENG exhibits exceptional durability and long-term stability. Moreover, the DS-TENG demonstrates tremendous potential in self-powered sensing of pressing and bending, monitoring human walking and sitting behaviors, and assisting pugilist training. This work provides a new design of compact self-supporting TENGs with reliable long-term performance and paves a cost-effective approach for green and scale fabrication of TENGs.

Fabrication of Thermoplastic Polyurethane Foams with Wrinkled Pores and Superior Energy Absorption Properties by CO2 Foaming and Fast Chilling

AbstractPrecise control and delicate manipulation of pore morphology are challenges for supercritical CO2 (scCO2) foaming of polymer foams to boost their performances and extend their applications. Herein, a simple two‐step scCO2 foaming and fast chilling method is proposed to fabricate thermoplastic polyurethane (TPU) foams with unique wrinkly structures inside the pores by introducing a fast cooling procedure in an ice water bath right after the foaming process. The combined effects of the increase of TPU surface tension and the decrease of CO2 pressure inside the pores induce intense intermolecular stress on the pore walls, which trigger the formation of micro‐sized wrinkles on the pore walls. The wavelength of the wrinkly structure can be reduced from 2.8 to 1.1 µm by raising the foaming temperature, which is associated with the wrinkled structure changing from hexagon to labyrinth. Compared with conventional foams, wrinkled foams possess superior compressive modulus, strength, and energy absorption performance, and wrinkled foams with wrinkles display better energy absorption. This study provides a facile approach to produce wrinkled foams with controllable morphology and gives insights into the remarkable compressive performance of the wrinkled foams, which make them promising materials for energy absorption applications.