Self-healing Feature Research Articles

Self-healing and superhydrophobic dual-function composite coating for active protection of magnesium alloys

Anti-corrosion inorganic-organic hybrid coating with the self-healing feature is still scare for the Mg alloys. The adhesion between various compositions is one troublesome problem. On the other hand, the incorporation of corrosion inhibitor would destroy the feature of organic film leading to the inferior anti-corrosion performance. The hybrid coating, PEO/IN/QSE, with the self-healing feature is firstly fabricated on Mg alloys, in which the corrosion inhibitor of imidazolium-based ionic liquid (IN) is embedded in the plasma electrolytic oxidation (PEO) pores and the superhydrophobic film (QSE) is covered on the top. The IN embedded in the pores of PEO layer does not destroy the feature of QSE film and improve the anti-corrosion performance of PEO layer. And it affords the self-healing function, which is determined by the anti-corrosion test with the scratched samples. More important, it strengthens the adhesion between QSE and PEO coating as a bridge. This work provides a feasible strategy to prepare the inorganic-organic composite film with the promising applications for the anti-corrosion of the Mg alloys.

Broadband ultrasonic focusing based on circular Airy-like beam

Convergence of ultrasonic energy is of great importance in the medical and engineering fields. In this work, ultrasonic focusing based on circular Airy-like beam (CALB) is numerically and experimentally demonstrated. The CALB focusing can be achieved simply using a planar resin ring lens immersed in water. At 2 MHz, the acoustic intensity at the focus can reach 257 times that for the incident wave. Arising from the self-healing feature of Airy beams, the CALB focusing can be well maintained even if there exists an obstacle in the acoustic path. Meanwhile, the focusing behaviour is well performed in a broad frequency range of 1.5 MHz to 3.1 MHz due to the simple and non-resonant design. By adjusting the frequency of the incident waves, the focal length can be modified without changing the lens structure. The CALB focusing and the corresponding planar lens may promote wide applications in ultrasound imaging, non-destructive testing, acoustic tweezing and medical diagnostic techniques.

Enhanced long-term corrosion resistance of Mg alloys by superhydrophobic and self-healing composite coating

Although Magnesium (Mg) alloys have many distinct advantages, they are vulnerable to the corrosion even in the neutral environment. Effective and feasible anti-corrosion strategies are desirable for the wide application of Mg alloys. A novel anti-corrosion composite coating, MAO (micro-arc oxidation)/[OTP][NTf2] (octadecyl triphenyl phosphonium bis(trifluoromethylsulfonyl)amide)/PSE (superhydrophobic silica/epoxy resin), is fabricated for Mg alloys by combination of MAO, ionic liquid, and superhydrophobic coating. The employed [OTP][NTf2] is incorporated into the pores of MAO coating rather than doped in the PSE coating. The successful preparation of composite coating is characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDXS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The anti-corrosion feature is measured by potentiodynamic polarization curves (PDP) and electrochemical impedance spectroscopy (EIS) in 3.5 wt% NaCl solution. The composite coatings maintain excellent corrosive resistance after 80 days immersion in 3.5 wt% NaCl solution. It is attributed to the synergistic effect of the superhydrophobic feature, the corrosion inhibition of [OTP][NTf2], and the physical barrier of the MAO coating. Even if the coating is scratched, it still exhibits the excellent anti-corrosion performance after immersion in 3.5 wt% NaCl solution for 25 days due to the repair ability of [OTP][NTf2]. The incorporation of [OTP][NTf2] not only offers the self-healing feature but also seals the pores on the MAO surface, which is favorable to enhance the overall anti-corrosion performance of composite coating.

Building Self-Healing Feature Based on Faster R-CNN Deep Learning Technique in Web Data Extraction Systems

Web data extraction has evolved over the years with extracting data from documents to today’s World Wide Web (WWW). The WWW growth has placed data at the centre of this ecosystem and benefited society at large, businesses and consumers. The proposed system uses deep learning technique, Faster region convolutional neural network (R-CNN) for automated navigation, extraction of data and self-healing of data extraction engine to adapt to dynamic changes in website layout. The proposed system trains the Faster R-CNN model for detection of product in the web page using bounding box image detection technique and extracts product details with high extraction accuracy. Deep learning technique has advanced rapidly in the different fields for image detection, but its application in data extraction makes this paper unique. An ecommerce retail website is used as real-world example to prove the self-healing capability of the proposed automated web data extraction system.

Surfactant-assisted fabrication of room-temperature self-healable dielectric elastomer toward actuation application

Dielectric elastomers are widely used for actuation applications in emerging domains such as tunable optics, tactile displays and soft robotics. However, dielectric elastomer actuators (DEAs) are prone to suffering from electrical or mechanical damage under the conditions of high operating voltage and mechanical stress, leading to a short service time and a low reliability. To address these issues, we in this work made an attempt to facilely develop a self-healable dielectric elastomer that combines high stretchability, dielectric properties, large actuation and effective repairing of mechanical and electrical failure by constructing multitype noncovalent interactions under surfactant assistance. It is demonstrated that the as-prepared elastomer possesses good healability at room temperature. After mechanical injury, a gentle pressure can initiate the recovery of damaged region, and the elastomer film could be subjected to a huge strain of 750% after healing for 24 h. In particular, this as-fabricated DEA that suffered from accidental or repetitive breakdown could still be re-actuated stably without significantly decreasing its actuated strain after quick healing (∼5 min). It is also found that embedding a fluoroelastomer with a fluorosurfactant can achieve larger deformation (tan α = 0.57 at 30 MV/m) due to the improved electromechanical properties. Our strategy for achieving self-healing feature and high actuation performance is favorable for extending lifetime, strengthening damage tolerance and lowering excitation voltages required for the DEAs.

Self-healing inorganic hydrated salt gels for personal thermal management in the static and dynamic modes

Thermal comfort is of great significance to maintain the normal metabolism of life. Personal thermal management (PTM) that passively regulates the immediate environment around the human body is a promising alternative. In this work, we report a state-of-the-art concept of self-healing inorganic hydrated salt gels (IHSGs) constructed by ionic crosslinking, covalent crosslinking and hydrogen bond crosslinking for wearable PTM. Sodium sulfate decahydrate (SSD) is selected as the energy storage medium on account of its phase change temperature near the human body temperature. The calcium alginate and the sodium polyacrylate construct the double gel network to anchor the SSD. The dynamic hydrogen bond and the dynamic ionic bond enable the self-healing feature of the SSD IHSGs. The proposed SSD IHSGs with 4% borax, 0.1% sodium hexametaphosphate and 8% sodium polyacrylate demonstrate suppressed phase separation, eliminated supercooling, highly form-stability, high instinct thermal conductivity (0.80 Wm-1K−1), high energy storage capacity (147.14 Jg−1), high self-healing rate (94.3%) and highly cost-effectiveness (energy storage cost 2.44 × 10-3 ¥J−1). Taking advantages of the above merits, the IHSGs are applied in wearable PTM in the static and dynamic modes to meet the thermal comfort requirements. It is anticipated that the one-stop IHSG solution offers great prospect for the advanced wearable PTM.

Resilient and Self-Healing Hyaluronic Acid/Chitosan Hydrogel With Ion Conductivity, Low Water Loss, and Freeze-Tolerance for Flexible and Wearable Strain Sensor.

Conductive hydrogel is a vital candidate for the fabrication of flexible and wearable electric sensors due to its good designability and biocompatibility. These well-designed conductive hydrogel–based flexible strain sensors show great potential in human motion monitoring, artificial skin, brain computer interface (BCI), and so on. However, easy drying and freezing of conductive hydrogels with high water content greatly limited their further application. Herein, we proposed a natural polymer-based conductive hydrogel with excellent mechanical property, low water loss, and freeze-tolerance. The main hydrogel network was formed by the Schiff base reaction between the hydrazide-grafted hyaluronic acid and the oxidized chitosan, and the added KCl worked as the conductive filler. The reversible crosslinking in the prepared hydrogel resulted in its resilience and self-healing feature. At the same time, the synthetic effect of KCl and glycerol endowed our hydrogel with outstanding anti-freezing property, while glycerol also endowed this hydrogel with anti-drying property. When this hydrogel was assembled as a flexible strain sensor, it showed good sensitivity (GF = 2.64), durability, and stability even under cold condition (−37°C).

A self-healing room-temperature liquid eutectic GaSn anode with improved wettability for advanced Mg ion batteries

Using alloy-type anodes offers an effective method to address the incompatibility issue between Mg metal anodes and conventional electrolytes and also facilitates the development of high performance magnesium ion batteries (MIBs). But the huge volume variations of alloy-type anodes during cycling impair the electrochemical performance of MIBs. Herein, a liquid eutectic GaSn (EGaSn) electrode with a low melting point (20.5 °C) and self-healing property was fabricated through simply painting onto stainless steel mesh (ssm). But the ssm-EGaSn electrode shows unsatisfactory electrochemical performance due to poor wettability of liquid EGaSn on ssm. To overcome this problem, a CuGa2 layer was constructed to enhance the wettability of liquid EGaSn on the ssm substrate. The modified liquid EGaSn electrode delivers much better electrochemical performance (specific capacity, cycling stability and rate performance) either at ∼ 38 or 28 °C. Furthermore, operando X-ray diffraction and ex situ scanning electron microscopy were conducted to reveal the Mg storage mechanism and self-healing feature of the liquid EGaSn electrode. Noticeably, the liquid EGaSn electrode displays well compatibility with simple Mg salt electrolytes like Mg(TFSI)2 and the full cell could display stable electrochemical behavior over dozens of cycles.

NIR light-triggered self-healing waterborne polyurethane coatings with polydopamine-coated reduced graphene oxide nanoparticles

Self-healing coatings that are able to self-repair after being damaged represent an effective solution to provide a reliable and long-lasting protection of the underlying substrate. In this work, we developed self-healing waterborne polyurethane (PU) coatings through the introduction of Diels-Alder bonds in the polymer backbone. Although heat is typically used as trigger, here we exploited photothermal converters to allow also NIR light-induced self-healing. To this aim, we synthesized (3-aminopropyl)-triethoxysilane-modified graphene oxide nanosheets that were subsequently coated by nanometric polydopamine particles, which serve for imparting to the coating the NIR-responsive self-healing feature. Fourier transform infrared and X-ray photoelectron spectroscopy confirmed the successful synthesis of PDA-coated reduced graphene oxide nanoparticles, which were thus exploited to prepare nanocomposite PU coatings on bronze substrates on which they exhibited good adhesion. Once scratched, fast and effective self-healing was ensured upon irradiation with NIR light for only 30 s. In addition, electrochemical impedance spectroscopy analyses proved that the nanocomposite coatings exhibited improved barrier properties which resulted in an enhanced protection of the underlying metal from corrosion.

Interfacial assembled mesoporous polydopamine nanoparticles reduced graphene oxide for high performance of waterborne epoxy-based anticorrosive coatings

Embedding two-dimension micro/nanocontainers containing corrosion inhibitors into organic coating is a well-established concept to impart the coating with enhanced barrier and self-healing feature. Herein, a versatile nanoemulsion assembly approach was used to synthesis nanocarriers combing mesoporous polydopamine nanoparticles (MPDA) with reduced graphene oxide (GO), which was employed to encapsulate corrosion inhibitors (benzotriazole, BTA) to improve the anticorrosion performance of waterborne epoxy coating. The BTA release profiles from synthesized GO with MPDA (PDAG) demonstrated the rapid pH-triggered activities to acidic corrosion environment. With the addition of BTA-loaded PDAG, the composited epoxy coatings presented self-repairing behavior and enhanced corrosion resistance during long-term immersion. The outstanding anticorrosion performance is attributed to dual-protection mechanism provided by BTA-loaded PDAG: (1) MPDA endows GO with satisfactory interface compatibilities and thus provides impermeable barrier to delay the penetration process of corrosive electrolyte; (2) corrosion inhibitors including BTA and polydopamine form the adsorption layers on bare steel surface to resist continuous corrosion at metal/coating interface.

A Wavy-Structured Highly Stretchable Thermoelectric Generator with Stable Energy Output and Self-Rescuing Capability

A Wavy-Structured Highly Stretchable Thermoelectric Generator with Stable Energy Output and Self-Rescuing Capability

Silica-based Janus nanosheets for self-healing nanocomposite hydrogels

As functional nanocomposites, Janus nanomaterials can play an important role due to their asymmetric structure and different components on the same surface. In this manuscript, hollow silicon spheres (SiO2 JHs) with an asymmetric structure were prepared by an emulsion interfacial self-organized sol-gel process. Inspired by mussel chemistry, the exposed surfaces of the SiO2 JHs were modified chemically by polydopamine (PDA). 2-(3-(6-Methyl-4-oxo-1,2,3,4-tetrahydropyrimidin-2-yl)ureido)ethyl methacrylate (MAUPy) containing multiple hydrogen bond groups were grafted to obtain SiO2@PDA/PMAUPy Janus Nanosheets (SiO2@PDA/PMAUPy JNs) by Pickering emulsion. The prepared SiO2@PDA/PMAUPy JNs were further applied to prepare nanocomposite self-healing hydrogels. As a result of the synergy of reversible non-covalent metal-ligand and hydrogen bonding, hydrogels with dual self-healing feature were successfully fabricated. The obtained hydrogels maintain preferable mechanical properties (strain of about 411.0% and stress of about 4.1 MPa) and excellent healing ratio (92.6%), which may have broad application prospects in smart flexible sensor and biomedical application.

Front Cover: Progress in aggregation‐induced emission‐active fluorescent polymeric hydrogels

Aggregation-induced emission (AIE)-active fluorescent polymeric hydrogels (FPHs) are the marriage of AIE-active materials and polymeric hydrogels. They are known to bear many advantageous properties such as soft wet nature, tissue-like mechanical strength, biocompatibility, biomimetic self-healing feature, facilely tailored structure, as well as responsive fluorescence and volume/shape changes, thus representing a promising category of luminescent materials with many frontiers uses. This Review is intended to give a systematic summary of the recent progress in this young but flourishing research area. (Article number 2021, 2, e37)

Polymer Stabilized Liquid Metal Nanodroplets As an Artificial Interphase Layer for Lithium Metal Anodes

Lithium (Li) metal batteries are considered to be the next-generation high energy density batteries because of the low reduction potential of metallic Li (−3.04 V) and its high specific capacity (3860 mA h g−1). However, there are challenges to implement lithium metal as an anode material. Especially the brittle and unstable solid electrolyte interface (SEI) formed by reaction of highly reactive lithium metal with liquid electrolytes, which can lead to low Coulombic efficiency and short cycle life.1 The design of an artificial SEI, i.e. ex-situ building of a protective layer on Li metal has shown to be effective for stabilizing Li metal anode and interphase. Especially, Li alloys can enable stable Li metal anodes by i) providing fast ion transport at the interphase, ii) suppressing the Li dendrites growth, iii) generating a stable interface between Li alloy anode and electrolyte, and iv) exhibiting high exchange currents, overall resulting in stable long-term performance.2 In 2017, Nazar et al. first reported a facile and scalable procedure to fabricate thin alloy layers onto Li metal foil via the in situ reduction of metal chlorides by Li.3 Two-metal component alloy and ternary alloy systems (based on Ga, Sn, In, Zn, Mg, Ag etc.) have also been investigated in Li-ion and alkali metal batteries. Goodenough et al. reported a lithium alloyed Ga-In nanoparticle/carbon/binder electrode. The liquid Ga-In system exhibited self-healing feature and high diffusivity in liquids, and the composite anode realized a high capacity and excellent stability in both Li-ion and Na-ion batteries.4 Herein, EGaIn consisting of 75 wt% Ga and 25 wt% In is chosen as a model liquid metal. An artificial SEI design based on poly(ethylene oxide)-block-poly(acrylic acid) (PEO-b-PAA) diblock copolymer was exploited to stabilize EGaIn nanodroplets. The attachment of polymer brushes onto EGaIn nanodroplets can greatly improve the dispersibility of nanoparticles, therefore creating a more uniform protection layer than bulk EGaIn. PAA chains are designed as anchoring blocks to attach onto the EGaIn “skin” layer via multiple coordination interactions, while PEO chains should ensure the ionic conductivity for Li ions transport. The molecular weight and molecular weight distribution of PAA can be precisely controlled by atom transfer radical polymerization (ATRP) (Figure 1a). Under ultrosonication, PEO-b-PAA act as polymeric surfactant to fabricate polymer-grafted-EGaIn nanodroplets through a “grafting onto” method via the PAA anchoring groups. This provides a general and robust strategy to achieve high colloidal stability and good dispersibility (Figure 1b). The artificial SEI was then fabricated on Cu current collector by spray coating, which is a facile strategy to form uniform and thin layers onto large surface area substrates. Galvanostatic Li electrodeposition voltage profiles for asymmetric Li cells (Cu|Li, Cu@EGaIn-PEO-b-PAA|Li) were conducted. The lower nucleation overpotentials on coated Cu compared to bare Cu illustrates that the EGaIn/PEO-b-PAA artificial SEI help Li to stably nucleate and uniformly grow the Li nuclei via interlayer gaps above and under the SEI. The artificial SEI regulate lithium deposition and enabes faster Li-ion transport and diffusion. In conclusion, polymer stabilized EGaIn nanodroplets used as artificial SEI can effectively protect Li metal anodes, further improving the capacity retention, Coulombic efficiency, and lifespan of Li metal batteries.Figure 1. a) Synthesis of PEO-b-PAA copolymer. b) Preparation of polymer stabilized EGaIn nanodroplets. c) Nucleation behavior of Li metal on artificial SEI modified Cu substrate. Figure 1

Lightweight and self-healing carbon nanotube/acrylic copolymer foams: Toward the simultaneous enhancement of electromagnetic interference shielding and thermal insulation

• Lightweight, self-healing carbon nanotube/acrylic copolymer foams were obtained. • The thermal conductivity of the foam is less than 0.019 W·m −1 ·K −1 . • EMI specific shielding effectiveness of the foams reaches to 1243.3 dB·cm 2 ·g −1 . • The healing effectiveness of the EMI shielding performance is greater than 79%. • The foams are used as magnetic interference shielding and thermal insulation. Electromagnetic interference (EMI) shielding foams featuring light weight and ultralow thermal conductivity have received attention in a diverse range of applications, but their limited service life makes them very challenging in realistic use. As such, prolonging their service life has aroused significant scientific and technical interest. Herein, we report a facile method to prepare a carbon nanotube/acrylic copolymer (CNT/AC) foam by using isobutane as a blowing agent. This strategy is effective in constructing a 3D porous architecture composed of a segregated CNT network impregnated with an AC polymer through a hot pressing foaming process. This unique structure endows the composite with superior EMI specific shielding effectiveness (for foams with 0.62 vol% CNTs: 1243.3 dB·cm 2 ·g −1 ) and an extremely low percolation threshold and thermal conductivity (0.008 W·m −1 ·K −1 ). More intriguingly, the inherent long-chain entanglements give the foam a self-healing feature. Specifically, with the incorporation of 0.80 vol% CNTs, the healing effectiveness of the EMI shielding performance is greater than 79% in the frequency range from 8.2 GHz to 12.4 GHz. Overall, the resulting CNT/AC foam possesses numerous advantages such as light weight, thermal insulation and EMI shielding self-healing performance, suggesting great potential application value in aviation areas.

Mechanical Properties of a Supramolecular Nanocomposite Hydrogel Containing Hydroxyl Groups Enriched Hyper-Branched Polymers.

Owing to highly tunable topology and functional groups, hyper-branched polymers are a potential candidate for toughening agents, for achieving supramolecular interactions with hydrogel networks. However, their toughening effects and mechanisms are not well understood. Here, by means of tensile and pure shear testings, we characterise the mechanics of a nanoparticle–hydrogel hybrid system that incorporates a hyper-branched polymer (HBP) with abundant hydroxyl end groups into the matrix of the polyacrylic acid (PAA) hydrogel. We found that the third and fourth generations of HBP are more effective than the second one in terms of strengthening and toughening effects. At a HBP content of 14 wt%, compared to that of the pure PAA hydrogel, strengths of the hybrid hydrogels with the third and fourth HBPs are 2.3 and 2.5 times; toughnesses are increased by 525% and 820%. However, for the second generation, strength is little improved, and toughness is increased by 225%. It was found that the stiffness of the hybrid hydrogel is almost unchanged relative to that of the PAA hydrogel, evidencing the weak characteristic of hydrogen bonds in this system. In addition, an outstanding self-healing feature was observed, confirming the fast reforming nature of broken hydrogen bonds. For the hybrid hydrogel, the critical size of failure zone around the crack tip, where serious viscous dissipation occurs, is related to a fractocohesive length, being about 0.62 mm, one order of magnitude less than that of other tough double-network hydrogels. This study can promote the application of hyper-branched polymers in the rapid evolving field of hydrogels for improved performance.

Self-healing flexible strain sensors based on dynamically cross-linked conductive nanocomposites

Self-healing, flexible, robust and adaptable strain sensors with intelligent skin-like features are greatly promising for future wearable devices. In this work, we demonstrate a self-healing flexible strain sensor with stretchability, robust mechanical strength, and high sensing sensitivity, which can monitor human motions. The sensor is constructed by the dynamically cross-linked conductive nanocomposite based on imine and quadruple hydrogen bonds. Due to the reversible interactions, the nanocomposites exhibit excellent self-healing performances with the healing efficiency up to 95%. The interfacial compatibility between the nanofillers and polymer networks is enhanced through the supramolecular interactions. Based on piezoresistive effects, the change of resistance for the nanocomposite-based strain sensor can be obviously observed under various deformation including stretching, bending, and twisting. Meanwhile, the gauge factor of the sensor reaches 46, showing high sensing sensitivity. Benefited from the self-healing feature, the sensor can withstand mechanical damage and restore the function of detecting human motions, enabling reliability and stability in practical applications, which shows great potential for developing smart wearable devices, healthcare monitoring, and human-machine interfaces.

Application of Numerical Simulation for Metallized Film Capacitors Electrodes Design

Polymer film capacitors are widely used in modern power equipment, because of excellent volumetric characteristics in combination with high-voltage application ability. Using segmented electrodes of nanometer thickness increased the capacitor's performance and reliability because of the self-healing feature. In this paper, we present the results of the experimental investigation and numerical simulation of electrothermal destruction of the metallized film capacitors segmented electrodes during the self-healing process. The destruction processes were investigated for both a single gate and single segment, comprising four parallel gates connected to the segment. The numerical simulation was conducted by means of COMSOL Multiphysics software. The model takes into account the heat flow from metal layer to polymer film since it has significant influence on the destruction process. Based on a good agreement of experimental and numerical results, the simulation model was proposed for the real metallized film capacitor segmented electrodes design. The model allows evaluating the single segment isolating time during self-healing, the energy required for the isolating, effective value of segmented electrodes surface resistance.

A highly responsive healing agent for the autonomous repair of anti-corrosion coatings on wet surfaces. In operando assessment of the self-healing process

A methodology to enrich epoxy coatings of an effective self-healing feature on wet surfaces was developed as a further step on for practical corrosion protection issues. To this aim, a polyetheramine was chemically engineered by grafting catechol units and then successfully encapsulated in microcapsules (MCs) to be finally embedded into an epoxy resin deposited on steel panels. Fourier transform infrared spectroscopy (FTIR), thin-layer chromatography, and 1D and 2D nuclear magnetic resonance spectroscopy confirmed the successful polyetheramine modification by dopamine units. Different dosages of catechol-modified polyetheramine were encapsulated within poly(styrene-co-acrylonitrile) shell via electrospray method to study the influence of dopamine grafting on the healing performance. Scanning electron microscopy (SEM) analysis revealed the formation of the spherical MCs, while FTIR and TGA analyses confirmed the successful encapsulation. The highly responsive self-healing coatings were then prepared by embedding amine- and isocyanate-containing MCs (1:1 weight ratio; 3 wt% overall) as a dual-capsule system exploiting the polyurea formation as a fast healing reaction. In operando electrochemical impedance spectroscopy (EIS) tests were employed to study the underwater self-healing performance. According to the EIS results, monotonically increasing variation with time of the charge transfer resistance was correlated with a fast and effective underwater self-healing performance for the sample using 40 wt% of a catechol-modified healing agent. Such results, combined with others including SEM investigation on the underwater healed samples, point to an improved adhesion of the growing dopamine-bearing polymer to both underlying metal and epoxy edges of the scratch.Graphic abstract

High-dimensional cryptography with spatial modes of light: tutorial

Fast and secure sharing of information is among the prime concerns of almost any communication system. While commonly used cryptographic algorithms cannot provide unconditional security, high-dimensional (HD) quantum key distribution (QKD) offers an exceptional means to this end. Here, we provide a tutorial to demonstrate that HD QKD protocols can be implemented in an effective way using optical elements that are known to most optics labs. We use spatial modes of light as our HD basis and show how to simulate QKD experiments with bright classical light, fostering its easy implementation for a more general audience including industry laboratories or laboratory classes in university teaching and in advanced laboratories for validation purposes. In particular, we use orbital angular momentum Bessel–Gaussian modes for our HD QKD demonstration to illustrate and highlight the benefits of using spatial modes as their natural Schmidt basis and self-healing feature.