Matthias Wessling

• Prof. Dr.-Ing.
• Professor at RWTH Aachen University

Electrochemical production of chemicals aims to enable the direct use of renewable electricity and sustainable resources such as biomass. A promising biobased product is the polymer furan-2,5-dicarboxylate (PEF). This polymer is synthesized from hemicellulosic biomass via the intermediates 5-hydroxymethylfurfural (HMF) and 2,5-furandicarboxylic aci...

Recent studies show the importance of hydrogel geometry for various applications, such as encoding, micromachines, or tissue engineering. However, fabricating hydrogel structures with micrometer‐sized features, advanced geometry, and precise control of porosity remains challenging. This work presents hierarchically structured hydrogels, so‐called h...

Artificial organs, such as extracorporeal membrane oxygenators, dialyzers, and hemoadsorber cartridges, face persistent challenges related to the flow distribution within the cartridge. This uneven flow distribution leads to clot formation and inefficient mass transfer over the device's functional surface. In this work, a comprehensive methodology...

Achieving adequate cell densities remains a major challenge in establishing economic biotechnological and biomedical processes. A possible remedy is microcarrier‐based cultivation in stirred‐tank bioreactors (STBR), which offers a high surface‐to‐volume ratio, appropriate process control, and scalability. However, despite their potential, commercia...

Ferrate (Fe(VI)) is of great interest in energy storage solutions, organic synthesis, and wastewater treatment due to its decent oxidation potential and non‐toxic end‐product formation, making it a green oxidizer. The electrochemical generation of ferrate in NaOH at current densities of j ≥ 100 mA cm⁻² is presented using low‐cost sacrificial iron a...

The transport and clogging behavior of flexible particles in confined flows is a complex interplay between elastic and hydrodynamic forces and wall interactions. While the motion of non-spherical particles in unbounded flows is well understood, their behavior in confined spaces remains less explored. This study introduces a coupled computational fl...

Vapor phase infiltration (VPI) has emerged as a promising tool for fabrication of novel hybrid materials. In the field of polymeric gas separation membranes, a beneficial impact on stability and membrane performance is known for several polymers with differing functional groups. This study for the first time investigates VPI of trimethylaluminum (T...

Electrochemical reduction of CO2 poses a vast potential to contribute to a defossilized industry. Despite tremendous developments within the field, mass transport limitations, carbonate salt formation, and electrode degradation mechanisms still hamper the process performance. One promising approach to tweak CO2 electrolysis beyond today's limitatio...

Electrochemical reduction of CO2 poses a vast potential to contribute to a defossilized industry. Despite tremendous developments within the field, mass transport limitations, carbonate salt formation, and electrode degradation mechanisms still hamper the process performance. One promising approach to tweak CO2 electrolysis beyond today’s limitation...

Coupling renewable electricity to reduce carbon dioxide (CO2) electrochemically into carbon feedstocks offers a promising pathway to produce chemical fuels sustainably. While there has been success in developing materials and theory for CO2 reduction, the widespread deployment of CO2 electrolyzers has been hindered by challenges in the reactor desi...

This work describes the fabrication of a novel electroconductive membrane made of Ti3C2Tx (MXene) nanosheet coating through a one‐step pressure‐assisted technique. Ti3C2‐MXene is firmly attached over a polyamide–imide (PAI) microfilter by employing a binder composed of carboxymethyl cellulose (CMC)/glutaraldehyde (GA). Through coating a proper amou...

The porous structure of microgels significantly influences their properties and, thus, their suitability for various applications, in particular as building blocks for tissue scaffolds. Porosity is one of the crucial features for microgel‐cell interactions and significantly increases the cells' accumulation and proliferation. Consequently, tailorin...

The coupling between ion transport, fluid flow, and electrostatics may give rise to electroconvection, a physical phenomenon in which the buildup of charge near selective surfaces leads to hydrodynamic instability, eventually transitioning to an unsteady and chaotic flow. Though electroconvection contains a wide range of spatiotemporal scales, aver...

Cell migration is a fundamental process underlying the morphological maturation of organs, but also in disease‐related conditions such as cancer. Cells are able to migrate through crowded space and a tight extracellular matrix (ECM). Passing through a constriction, a cell deforms strongly, including its nucleus. Such nuclear deformation can lead to...

The use of gas diffusion electrodes (GDEs) enables efficient electrochemical CO2 reduction and may be a viable technology in CO2 utilization after carbon capture. Understanding the spatio‐temporal phenomena at the triple‐phase boundary formed inside GDEs remains a challenge; yet it is critical to design and optimize industrial electrodes for gas‐fe...

Convective drying of porous media is central to many engineering applications, ranging from spray drying over water management in fuel cells to food drying. To improve these processes, a deep understanding of drying phenomena in porous media is crucial. Therefore, detailed simulation of multiphase flows with phase change is of great importance to i...

Foam formation is a massive challenge in submerged aerated bioprocesses, e.g., in beer fermentation. While the use of antifoam may easily overcome foaming at laboratory scale, it is often an unattractive solution since the challenge remains in future upscaling, as reduced mass transfer and extra steps in product purification and analytics result in...

Electrochemical CO 2 reduction is a promising way of harnessing greenhouse gas as an abundant resource for the production of value-added hydrocarbons. By employing copper as the catalyst, CO 2 can be converted to multi-carbon compounds such as ethylene. Highly porous gas diffusion electrodes (GDEs) enable efficient contacting of gaseous CO 2 and th...

For most applications, especially transport, hydrogen needs to be compressed due to its low volumetric density. Conventionally, mechanical compressors are used for hydrogen compression, but they possess disadvantages such as high maintenance due to moving parts and a limited one-stage compression ratio. A promising technology to overcome those obst...

Electrochemical reactions are limited to the surface of the electrode, which makes the construction and intensification of electrochemical processes challenging. To increase the space-time yield of electrochemical cells, the electrochemically active surface area has to be enlarged. This can be achieved by either increasing the surface of a fixed el...

Emerging micropollutants (MPs) in water bodies such as pharmaceuticals, pesticides, personal care products, and per-and poly-fluoroalkyl substances (PFAS) have posed environmental, ecological, and anthropological issues since MPs are too persistent to be degraded by conventional biological treatment. On the other hand, electrochemical advanced oxid...

Biobased platform chemicals and energy carriers can replace conventional, fossil-based chemicals and fuels to decrease the footprint of the chemical industry in the future. Promising chemicals for this purpose are 2,5-furandicarboxylic acid (FDCA), a monomer for biobased polymers, and 2-butanone, a solvent and energy carrier. Both molecules can be...

Additive manufacturing techniques continue to improve in resolution, geometrical freedom, and production rates, expanding their application range in research and industry. Most established techniques, however, are based on layer‐by‐layer polymerization processes, leading to an inherent trade‐off between resolution and printing speed. Volumetric 3D...

Photocatalytic water treatment is considered a promising technique to prevent micropollutants from entering the environment. However, no off-the-shelf UV reactors on lab scale are available to study new processes and photocatalysts. In this study, we present a tubular UV reactor equipped with 30 UV-LEDs, emitting UV light at 367 nm and a total radi...

Microporous annealed particle (MAP) scaffolds are investigated for their application as injectable 3D constructs in the field of regenerative medicine and tissue repair. While available MAP scaffolds provide a stable interlinked matrix of microgels for cell culture, the infiltration depth and space for cells to grow inside the scaffolds is pre‐dete...

This feature article presents insights concerning the correlation of plasma‐enhanced chemical vapor deposition and plasma‐enhanced atomic layer deposition thin film structures with their barrier or membrane properties. While in principle similar precursor gases and processes can be applied, the adjustment of deposition parameters for different poly...

Additive manufacturing (AM) is a promising alternative to conventional electrode production due to its high freedom of design, excellent reproducibility, and a manifold choice of metals serving as substrates or even electrocatalysts in various electrochemical reactions. Nonetheless, porous gas diffusion electrodes (GDEs) have not been fabricated by...

In a single-step spinning process, we create a thin-walled, robust hollow fiber support made of Torlon® polyamide-imide featuring an intermediate polyethyleneimine (PEI) lumen layer to facilitate the integration and covalent attachment of a dense selective layer. Subsequently, interfacial polymerization of m-phenylenediamine and trimesoyl chloride...

Membrane-based CO$_2$ removal from exhaust streams has recently gained much attention as a means of reducing emissions and limiting climate change. Novel membranes for CO$_2$ removal include so called facilitated transport membranes (FTMs), which offer very high selectivities for CO$_2$ while maintaining decent permeabilities. Recently, these FTMs...

Vasculogenesis and angiogenesis are leveraged by orchestrated secretion of several growth factors. Mimicking this process in vitro can maximize vascularization inside 3D cell cultures. While the role of individual growth factors, such as vascular endothelial growth factor, Ephrin‐B2, angiopoietins, and platelet‐derived growth factor‐BB (PDGF‐BB) is...

Neural interfaces are evolving at a rapid pace owing to advances in material science and fabrication, reduced cost of scalable complementary metal oxide semiconductor (CMOS) technologies, and highly interdisciplinary teams of researchers and engineers that span a large range from basic to applied and clinical sciences. This study outlines currently...

In vitro environments that realize biomimetic scaffolds, cellular composition, physiological shear, and strain are integral to developing tissue models of organ-specific functions. In this study, an in vitro pulmonary alveolar capillary barrier model is developed that closely mimics physiological functions by combining a synthetic biofunctionalized...

Electro-Fenton (EF) represents an eco-friendly and cost-effective advanced oxidation process that can remove highly persistent and hazardous pharmaceuticals, e.g., contrast media agents, from water bodies. However, up to date, EF modules incorporate a planar carbonaceous gas diffusion electrode (GDE) cathode containing fluorinated compounds as poly...

This feature article presents insights concerning the correlation of PECVD and PEALD thin film structures with their barrier or membrane properties. While in principle similar precursor gases and processes can be applied, the adjustment of deposition parameters for different polymer substrates can lead to either an effective diffusion barrier or se...

Activated carbon (AC) particles constitute the current material of choice concerning the preparation of flow electrodes for flow‐electrode capacitive deionization (FCDI). They are inexpensive, mass‐producible, highly conductive, and exhibit a large specific surface area for ion adsorption. However, despite recent advances concerning the modificatio...

A Proton flow reactor (PFR) system stores energy in the form of hydrogen in porous carbon particles in slurry electrodes. However, the hydrogen storage mechanisms and the reactions in this system are not well understood. In this study we design and fabricate a microfluidic proton flow reactor (MPFR) as a small-scale PFR to enable in-situ visualisat...

Recreating human tissues and organs in the petri dish to establish models as tools in biomedical sciences has gained momentum. These models can provide insight into mechanisms of human physiology, disease onset, and progression, and improve drug target validation, as well as the development of new medical therapeutics. Transformative materials play...

Organic neuromorphic devices can accelerate neural networks and integrate with biological systems. Devices based on the biocompatible and conductive polymer PEDOT:PSS are fast, require low amounts of energy and perform well in crossbar simulations. However, parasitic electrochemical reactions lead to self-discharge and the fading of learned conduct...

Reducing carbon dioxide to value‐added chemicals by electrolysis is a promising strategy to substitute fossil‐based processes. Research on CO2 electrolysis has vastly progressed, focusing on catalysis and electrode design, leaving an essential question on the central part of the electrolyzer: Which type of ion exchange membrane is best suited for C...

The modification of membranes with polyelectrolytes via the Layer-by-Layer (LBL) method has become state of the art in recent years. It is used to fabricate nanofiltration hollow fiber membranes or to immobilize biomolecules on a membrane surface. However, it still remains a time consuming process. In contrast, this work explores a single-step memb...

The conventional anodic oxygen evolution (OER) in electrochemical CO2 reduction (CO2R) needs to be replaced as it accounts for a major share in energy consumption while being a product of little to no value. In this work, we replace OER by glycerol oxidation reaction (GOR) to synthesize products such as formate, lactate and glycolate. Hereby, for t...

Tuning the pore size distribution of hemodialysis membranes is essential for the membrane’s selectivity and significantly affects the quality of the dialysis treatment. Tailoring the membrane’s molecular weight cut-off appropriately balances the removal of middle-molecular-weight uremic toxins while avoiding albumin loss. This undesirable albumin l...

The electrochemical chlor-alkali electrolysis remains an energy-intensive production process even though many improvements have been developed over the last decades. Oxygen depolarized cathodes (ODC) reduce energy consumption by approximately 25% while oxygen is consumed instead of hydrogen being evolved. The switchable ODC (sODC) facilitates the o...

Complex‐shaped microgels are promising building blocks for soft metamaterials. Their active and remote orientational control provides significant potential in architecting them in time and space. This work describes the use of magnetically actuable microgels of complex shape for spatio‐temporal flow control and showcases the concept for microfluidi...

Textile production is one of the main sources of freshwater consumption by industries worldwide. In addition, according to the world bank, 20 % of the wastewater generated globally is caused by textile wet-processing. Textile wet-processing includes the processes in textile production where garments are dyed or given the final functions like water-...

Utilizing CO2 as a resource for CO production in electrochemical reactors requires gas diffusion electrodes (GDE) that maintain a stable and highly reactive gas/liquid/solid interface. When scaling the process towards industrial application, the pressure difference in the electrolyte channel increases, amplifying instabilities at the multi-phase bo...

Bioreactors are the operative backbone, for example, for the production of biopharmaceuticals, biomaterials in tissue engineering, and sustainable substitutes for chemicals. Still, the Achilles' heel of bioreactors nowadays is the aeration which is based on intense stirring and gas sparging, yielding inherent drawbacks such as shear stress, foaming...

New membrane geometries have the potential to increase mixing at the feed and permeate side to counteract concentration polarization and fouling. Such membrane geometries can be of very different architecture. Here, we address a new class of hollow fiber membranes having helical ridges. We focus on gas–liquid mass transfer, which is significantly s...

Microfluidic systems offer a multitude of advantages over classical techniques in the fields of biomedical and chemical research. Unit operations such as sample pre‐treatment, mixing, reactions, and especially separation and purification operations can be realized on microfluidic platforms enabling rapid prototyping and facile parallelization on th...

Rhamnolipids are biosurfactants that tend to cause strong foaming, making microbial production in an aerated stirred tank fermenter challenging. The continuous removal of rhamnolipids from the cultivation broth via in situ liquid-liquid extraction can remedy this foam challenge, and thereby supports long-term cultivation and production. However, fo...

Complex geometries for electrodes are a great challenge in electrochemical applications. Slurry electrodes have been one example, which use complex flow distributors to improve the charge transfer between the current collector and the slurry particles. Here we use titanium‐based flow distributors produced by indirect 3D‐printing to improve further...

Intertwined electrode pairs, manufactured by selective laser melting, provide high surface‐to‐volume ratios and a constant interelectrode distance, which results in a homogeneous electric field. Gyroid convective channels are integrated into the structure to further enhance convective transport. Further details can be found in the article number 22...