Albertus P H J Schenning

• PhD
• Professor (Full) at Eindhoven University of Technology

Cholesteric liquid crystal oligomer coatings are promising smart materials for use as near infrared thermochromic reflectors to control solar radiation through windows. However, their effectiveness as solar energy transmission modulators is limited because they only reflect circularly polarized light of a specific handedness (either right‐ or left‐...

Mechanochromic polymers are receiving much attention for monitoring the structural performance of materials. Current mechanochromic polymers however do not offer simultaneous detection of the duration and degree of strain while retaining memory of the strain history. Here a structurally colored polymer coating is reported that can indicate, quantif...

Stimuli responsive optical materials are attractive for many areas, from healthcare to art design. However, creating intricate color‐changing patterns for visual information is still a challenge. This work describes the preparation of mechanochromic structural colored intricate pictures imprinted in cholesteric liquid crystal elastomers by using a...

For visible light reflective cholesteric liquid crystal polymers, reactive chiral dopant enantiomers with high helical twisting power are attractive. However, a chiral dopant for reflecting left-handed circularly polarized light has...

Smart surfaces, distinguished by their dynamic responses to environmental changes, may enhance the functionality, interactivity, and efficiency of materials and devices. Liquid crystal elastomers (LCEs) are ideal candidates for creating smart surfaces, allowing reversible topographical changes in response to environmental stimuli. However, traditio...

Stimuli responsive optical materials are attractive for many areas, from healthcare to art design. However, creating intricate color‐changing patterns for visual information is still a challenge. This work describes the preparation of mechanochromic structural colored intricate pictures imprinted in cholesteric liquid crystal elastomers by using a...

Structurally coloured responsive materials provide an interesting avenue for the development of autonomous temperature regulating window films. One interesting class of such thermochromic materials is cholesteric liquid crystals. However, cholesteric liquid crystals have rarely been applied in coatings for smart window applications. In this work, w...

Liquid crystal elastomer (LCE) actuators are generally limited in shape, size, and quantity by the need for aligning via stretching and fixing via photopolymerizing. A thermoplastic LCE is presented that may be vacuum thermoformed into centimeter‐sized hemispheres. The scalable industrial process induces LCE alignment without requiring postfixing....

4D microstructured actuators are micro-objects made of stimuli-responsive materials capable of induced shape deformations, with applications ranging from microrobotics to smart micropatterned haptic surfaces. The novel technology dual-wavelength volumetric microlithography (DWVML) realizes rapid printing of high-resolution 3D microstructures and so...

Photochromic smart windows have drawn increasing attention as an approach to improve building energy efficiency and enhance indoor daylight comfort. However, existing photochromic smart windows still block sunlight from entering the room on sunny winter days, causing additional energy consumption for heating. Herein, a dual‐mode smart window is des...

Sticky-colored labels are an efficient way to communicate visual information. However, most labels are static. Here, we propose a new category of dynamic sticky labels that change structural colors when stretched. The sticky mechanochro-mic labels can be pasted on flexible surfaces such as fabric and rubber or even on brittle materials. To enhance...

Glaucoma drainage devices are implanted in the eye to treat glaucoma, a disease that can cause vision loss and blindness. These devices are designed to reduce intraocular pressure (IOP), a major risk factor for the progression of glaucoma, by providing an alternative outflow path for the fluid produced by the eye, the aqueous humor. Here, a novel p...

Cholesteric liquid crystal oligomers are an interesting class of temperature responsive structurally, colored materials. However, the role of endcap molecules in these oligomers is rather unexplored. In this work, we demonstrate the role of endcap molecules on structural color stability and hypsochromic shift in temperature‐responsive cholesteric l...

The adaptive control of sunlight through photochromic smart windows could have a huge impact on the energy efficiency and daylight comfort in buildings. However, the fabrication of inorganic nanoparticle and polymer composite photochromic films with a high contrast ratio and high transparency/low haze remains a challenge. Here, a solution method is...

The extracellular environment defines a physical boundary condition with which cells interact. However, to date, cell response to geometrical environmental cues is largely studied in static settings, which fails to capture the spatiotemporally varying cues cells receive in native tissues. Here, a photoresponsive spiropyran‐based hydrogel is present...

Charge transfer complexes (CTCs) based on self-assembled donor and acceptor molecules allow light absorption of significantly redshifted wavelengths to either the donor or acceptor. In this work, we demonstrate a CTC embedded in a hydrogen-bonded liquid crystal elastomer (LCE), which in itself is fully reformable and reprocessable. The LCE host act...

Untethered soft fiber actuators are advancing toward next‐generation artificial muscles, with rotating polymer fibers allowing controlled rotational deformations and contractions accompanied by torque and longitudinal forces. Current approaches, however, are based either on non‐recyclable and non‐reprogrammable thermosets, exhibit rotational deform...

Windows serve the purpose of connecting room inhabitants with the outside environment, playing an important role in sustaining human health and well‐being. Windows also have a large impact on the lighting, heating, and cooling costs of indoor spaces. In this review, we discuss research over the past 5 years on “smart” windows based on organic mater...

Fibrosis of the filtering bleb is one of the main causes of failure after bleb-forming glaucoma surgery. Intraoperative application of mitomycin C (MMC) is the current gold standard to reduce the fibrotic response. However, MMC is cytotoxic and one-time application is often insufficient. A sustained-release drug delivery system (DDS), loaded with M...

Motivated by the need for efficient purification methods for the recovery of valuable resources, we developed a wire-electrospun membrane adsorber without the need for post-modification. The relationship between the fiber structure, functional-group density, and performance of electrospun sulfonated poly(ether ether ketone) (sPEEK) membrane adsorbe...

While dynamic surface topographies are fabricated using liquid crystal (LC) polymers, switching between two distinct 3D topographies remains challenging. In this work, two switchable 3D surface topographies are created in LC elastomer (LCE) coatings using a two‐step imprint lithography process. A first imprinting creates a surface microstructure on...

Multi‐stimuli responsivity in 3D‐printed objects is receiving much attention. However, the simultaneous interplay between different environmental stimuli is largely unexplored. In this work, we demonstrate direct ink writing of an oligomeric ink containing an azobenzene photo‐switch with an accessible hydrogen bond allowing triple responsivity to l...

Soft and mechanically responsive actuators hold the promise to revolutionize the design and manufacturing of devices in the areas of microfluidics, soft robotics and biomedical engineering. In many of these applications, the actuators need to operate in a wet environment that can strongly affect their performance. In this paper, we report on the ph...

Liquid crystalline polymers are attractive materials for untethered miniature soft robots. When they contain azo dyes, they acquire light‐responsive actuation properties. However, the manipulation of such photoresponsive polymers at the micrometer scale remains largely unexplored. Here, uni‐ and bidirectional rotation and speed control of polymeriz...

Multifunctional e-skins provide information on physiological and environmental parameters. However, the development and fabrication of such devices is challenging. Here, structural coloured electronic skins are presented, which are prepared via...

Cholesteric liquid crystal oligomers are widely researched for their interesting thermochromic properties. However, structure-property relationships to program the thermochromic properties of these oligomers have been rarely reported. In this work, we use the versatile thiol-ene click reaction to synthesize a series of hetero-oligomers and study th...

Recent years have seen major advances in the additive manufacturing of stimuli‐responsive materials, also known as “4D printing,” among which liquid crystal elastomers (LCEs) play an important role. However, during fabrication photo‐crosslinking of the LCEs is required, but this step is time‐consuming and efficient polymerization is challenging, es...

The type of glazing implemented in a building plays an important role in the heat management of a building. Solar heat entering through glazing causes overheating of interior spaces and increases building’s cooling load. In this work, the energy saving potential of window films based on Cholesteric Liquid Crystals (CLC) is explored. This emerging t...

For preserving food packed in environmentally friendly and recyclable paperboard packages, it is important to have sufficient gas barrier performance of the paperboard container. Paperboard has poor intrinsic barrier properties and to overcome this deficiency, so a barrier coating is needed that does not hinder the recycling of the paperboard subst...

Recently researchers have developed soft actuators capable of morphing into complex shapes taking inspiration from nature. In this paper, we have developed a splay‐nematic liquid crystal polymer network tapered actuator that can morph from a flat film to a cone, mimicking the blooming of single petal Calla Lily flower. We have demonstrated the form...

The gas separation performances of free-standing planar aligned nematic LC polymer films were investigated for gas separations of He, CO2, CH4 and Xe. The films consist of derivatives of 1,4-phenylene bis(4-((6-(acryloyloxy)hexyl)oxy)benzoate)s with respective cyano, chloro, methyl and phenyl substituents on the central aromatic cores. Two new LC d...

Envisioning robotic devices with functionality resulting from processing rather than exclusively material composition, multimodal responsive devices produced from a single azobenzene‐functionalized cholesteric liquid crystal elastomer ink are demonstrated. The resulting device displays simultaneous structural color and actuation in response to both...

Azobenzene liquid crystal polymers offer the potential to fabricate autonomously operated actuators remotely controlled by light. Usually, in fully polymerized actuators, only three different states can be obtained: the initial state, the metastable light-actuated state, and the recovered state, where the first and last states are identical and sta...

The UV intensity during photopolymerization allows control over the structural color of a cholesteric liquid crystal (CLC) polymer photonic coating in a single step. Simultaneously, the glass transition temperature (Tg) of the polymer can be tuned by the applied UV intensity. Most likely the low intensity photopolymerization increases the inhibitio...

Hydrogen‐bonded cyclohexanoic derivatives are applied in a structural colored cholesteric liquid crystal (CLC) helical polymer that demonstrates an extraordinary dual thermal response. Integration of the dynamic hydrogen‐bonded cyclohexanoic acid derivatives in the CLC polymer as supramolecular crosslinks yields an immediate and irreversible loss o...

Low molecular weight cholesteric liquid crystals (CLCs) can be trapped as droplets or particles inside a polymer binder, forming polymer dispersed cholesteric liquid crystal (PDCLC) systems, which are typically used for smart windows, displays, and optical sensors. While dispersing a single CLC mixture via emulsification, rendering reflective PDCLC...

The effect of layer spacing and halogenation on the gas separation performances of free-standing smectic LC polymer membranes is being investigated by molecular engineering. LC membranes with various layer spacings and halogenated LCs were fabricated while having a planar aligned smectic morphology. Single permeation and sorption data show a correl...

Despite progress in the field of electrochromic devices, developing structural color-tunable photonic systems having both high transparency and flexibility remains challenging. Here, an ink-deposited transparent electrochromic structural colored foil displaying reflective colors, tuned by an integrated heater, is prepared in a single-substrate meth...

Animals can modify their body shape and/or color for protection, camouflage and communication. This adaptability has inspired fabrication of actuators with structural color changes to endow soft robots with additional functionalities. Using liquid crystal-based materials for actuators with structural color changes is a promising approach. In this r...

Multiresponsive Liquid Crystal Cilia In article number 2101619, Dirk J. Broer and co‐workers prepare an array of liquid crystal polymer micro‐cilia of well‐defined tapered shape by replicating a track‐etched polyimide. The densely packed self‐standing cilia show patterned and collective out‐of‐plane motion in response to ambient changes. The bendin...

Using paperboard as packaging material is more sustainable than using plastic. To be a viable replacement, however, the barrier properties of paperboard need to be improved. Applying a waterborne barrier coating for both oil and water is an attractive method to improve the barrier performance of paperboard food packaging. However, not much is known...

The incorporation of photoswitches and photothermal dyes into liquid‐crystal polymers (LCPs) enables various light‐addressable shape changes. The anisotropic structure of LCPs allows for a conversion of molecular into macroscopic motion. Precise control of intensity and spatial resolution offers a large toolkit in fabrication, product design, senso...

Direct ink writing (DIW) of liquid crystal elastomers (LCEs) has rapidly paved its way into the field of soft actuators and other stimuli-responsive devices. However, currently used LCE systems for DIW require postprinting (photo)polymerization, thereby forming a covalent network, making the process time-consuming and the material nonrecyclable. In...

Additive manufacturing with stimuli‐responsive materials—4D printing—is a rapidly growing field, with direct ink writing allowing deposition of a wide variety of materials. The synthesis of a humidity‐sensitive cholesteric liquid crystal oligomer ink is reported. With the responsive cholesteric ink, demonstrator devices exhibiting the ink's “four d...

Cuttlefish can modify their body shape and both their pigmentary and structural colors for protection. This adaptability has inspired the development of appearance-changing polymers such as structural color actuators, although in most cases, the original shape has been confined to being flat, and pigmented structural color actuators have not yet be...

Polymer indicators are autonomous responsive materials that provide an optical signal of a specific exposure in time. This review describes the different polymer systems utilized to obtain indicators based on structural color. Structural color originates from the interaction of light with a periodic nanostructured polymer which causes a specific wa...

Cilia are of vital importance for myriad of natural functions such as the propulsion of microorganisms or the cleaning of the mammalian respiratory system. These cilia often show coupled 3D shape changes, such as waves, to perform their function. Here, we present a versatile platform to fabricate artificial micrometer‐sized azobenzene‐doped liquid...

Untethered Microactuators In article number 2100158, Marc del Pozo, Larisa Florea, Albert P. H. J. Schenning, and co‐workers present a new liquid crystalline photoresist for the creation of untethered microactuators using direct laser writing by two‐photon polymerization. The presented responsive microstructures have a high crosslink density that f...

The replacement of plastic packaging by paperboard can significantly contribute to meet sustainability goals in important application fields, such as in food packaging. The (water) barrier properties of paperboard-based products need, however, to be improved. Waterborne coatings offer an environmentally friendly possibility to enhance these barrier...

Both temperature-responsive and patterned photonic coatings are receiving a lot of attention from a fundamental and application point of view. However, the fabrication of multicolor patterns, which are also temperature-responsive, remains challenging. The current work presents a thermochromic photonic coating with light polarization-dependent multi...

The application of reprocessable and reprogrammable soft actuators is limited by the synthetic strategies, 3D‐shaping capabilities, and small deformations. In this work, melt‐processable supramolecular soft actuators based on segmented copolymers containing thiourethane and liquid crystal segments have been prepared via sequential thiol addition re...

The development of functionalized polyolefins for use as stimuli-responsive commodity polymers has recently received much attention. In this work, a microporous polypropylene (PP) scaffold is used to align and fortify a smectic liquid crystalline network (LCN) which can switch its gas permeability upon pH changes. The LCN is a photopolymerized liqu...

Soft actuators allowing multifunctional, multishape deformations based on single polymer films or bilayers remain challenging to produce. In this contribution, direct ink writing is used for generating patterned actuators, which are in between single- and bilayer films, with multifunctionality and a plurality of possible shape changes in a single o...

Over the past decade, progress in direct laser writing by two-photon polymerization (DLW-TPP) of stimuli-responsive materials has made considerable inroads into the realization of microactuators. With the focus on performing complex tasks such as walking, grasping, or delivering drugs, these actuators require a controlled preprogrammed actuation. L...

We report on the synthesis of monodisperse, flower‐like, liquid crystalline (LC) polymer particles by precipitation polymerization of a LC mixture consisting of benzoic acid‐functionalized acrylates and disulfide‐functionalized diacrylates. Introduction of a minor amount of redox‐responsive disulfide‐functionalized diacrylates (≤10 wt %) induced th...

The application of reprocessable and reprogrammable soft actuators is limited by the synthetic strategies, 3D‐shaping capabilities, and small deformations. In this work, melt‐processable supramolecular soft actuators based on segmented copolymers containing thiourethane and liquid crystal segments have been prepared via sequential thiol addition re...

Recent years have seen major advances in the developments of both additive manufacturing concepts and responsive materials. When combined as 4D printing, the process can lead to functional materials and devices for use in health, energy generation, sensing, and soft robots. Among responsive materials, liquid crystals, which can deliver programmed,...

To prevent greenhouse emissions into the atmosphere, separations like CO2/CH4 and CO2/N2 from natural gas, biogas, and flue gasses are crucial. Polymer membranes gained a key role in gas separations over the past decades, but these polymers are often not organized at a molecular level, which results in a trade-off between permeability and selectivi...

Chiral Photonic Polymers In article number 2103309, Albertus P. H. J. Schenning, Michael G. Debije, and co-workers show that using direct ink writing, unconventional chiral nematic objects can be generated, which show a bright iridescent color from normal incidence, or only from sharp angles of observation depending on the writing speed. The cover...

Polymerization techniques such as suspension, mini‐emulsion, dispersion, and precipitation polymerization produce LC polymer particles of various sizes, LC phases, and molecular alignments, and hence should be used in accordance with the targeted properties. The particles have found applications as rotors, absorbents, cell scaffolds, reflectors, ac...

Despite the plethora of available anisotropic inorganic particles, it remains challenging to fabricate non‐spherical polymer particles, especially with angular features. Here we report on the synthesis of monodisperse, flower‐like, liquid crystalline (LC) polymer particles by precipitation polymerization of an LC monomer mixture consisting of benzo...

Liquid‐crystalline polymer particles prepared by classical polymerization techniques are receiving increased attention as promising candidates for use in a variety of applications including micro‐actuators, structurally colored objects, and absorbents. These particles have anisotropic molecular order and liquid‐crystalline phases that distinguish t...

Hydrogen-bonded liquid crystalline polymers have emerged as promising “smart” supramolecular functional materials with stimuli-responsive, self-healing, and recyclable properties. The hydrogen bonds can either be used as chemically responsive (i.e., pH-responsive) or as dynamic structural (i.e., temperature-responsive) moieties. Responsiveness can...

The iridescence of structural color and its polarization characteristics originate from the nanoscale organization of materials. A major challenge in materials science is generating the bright, lustrous hues seen in nature through nanoscale engineering, while simultaneously controlling interaction of the material with different light polarizations....

Materials that rapidly change their optical properties in response to external stimuli are crucial for displays and ‘smart’ window applications. In this work, we describe a fluorescent red dye modified with liquid crystal side chains to be interactive with a liquid crystal host resulting in a color-tunable triple state smart window. The dye solubil...

Monodisperse, micrometer-sized liquid crystalline (LC) shells are prepared by seeded dispersion polymerization. After polymerizing LC monomer mixtures in the presence of non-crosslinked polymer seeds, hollow LC polymer shells with programmable alignment and shape are prepared by removing the seeds. The LC alignment in the LC polymer shells can be e...

In this work, the formation of triple-shape-memory liquid crystalline-interpenetrating polymer network (LC-IPN) actuators based on a hybrid acrylate-oxetane LC mixture is reported. Orthogonal polymerization of the oxetane and acrylate liquid crystals creates polymer films with two distinct glass-transition temperatures. The use of these two transit...

Polymer composites have attracted increasing interest as thermal management materials for use in devices owing to their ease of processing and potential lower costs. However, most polymer composites have only modest thermal conductivities, even at high concentrations of additives, resulting in high costs and reduced mechanical properties, which lim...

Cholesteric liquid crystals (CLCs) are a major class of photonic materials that display selective reflection properties arising from their helical ordering. The temperature response of CLCs, comprising of dynamic reflection color changes upon variation of temperature, can be exploited using material systems consisting of small mesogenic molecules,...

Untethered, light‐responsive, high‐stress‐generating actuators based on widely‐used commercial polymers are appealing for applications in soft robotics. However, the construction of actuators that are stable and reversibly responsive to low‐intensity ultraviolet, visible, and infrared lights remains challenging. Here, transparent, stress‐generating...

We report on the wavelength‐selective photopolymerization of a hybrid acrylate‐oxetane cholesteric liquid crystal monomer mixture. By controlling the sequence and rate of the orthogonal free‐radical and cationic photopolymerization reactions, it is possible to control the degree of phase separation in the resulting liquid crystal interpenetrating n...