Publications by Esther Amstad | EPFL Graph Search

Direct laser writing of electronically conductive microstructures within soft hydrogel substrates

Stéphanie Lacour, Esther Amstad, Outman Akouissi, Lorenzo Lucherini

Hydrogels have emerged as promising materials for bioelectronic interfaces due to their tissue-like properties and high-water content. However, conventional hydrogels often suffer from poor electrical conductivity and mechanical stability, limiting their p ...

2025

Direct Ink Writing of Rigid Microparticles

Esther Amstad

Direct ink writing (DIW) enables 3D printing of macroscopic objects with well-defined structures and compositions that controllably change over length scales of order 100 µm. Unfortunately, only a limited number of materials can be processed through DIW be ...

2025

Microstructured thermo-responsive double network granular hydrogels

Esther Amstad, Alexandra Thoma

Thermo-responsive double network granular hydrogels made of microgels with open micrometer-sized pores can lift up to 85% of their own weight and respond up to 3-fold faster to changes in temperature than bulk counterparts are introduced. ...

Royal Society of Chemistry (RSC)2025

Mechanoreceptive soft robotic molluscoids made of granular hydrogel-based organoelectronics

Esther Amstad, Nana Obayashi, Lorenzo Lucherini, Francesca Bono, Josephine Anna Eleanor Hughes

The viscoelasticity of many soft polymers renders flexible sensors susceptible to hysteresis and signal drift that limit their accuracy. To reduce the impact of viscoelasticity on the signal without compromising the softness of the material, we introduce e ...

2025

3D printing of self-healing longevous multi-sensory e-skin

Esther Amstad, Francesca Bono, Josephine Anna Eleanor Hughes, Sudong Lee

Electrically conductive hydrogels can simulate the sensory capabilities of natural skin, such that they are well-suited for electronic skin. Unfortunately, currently available electronic skin cannot detect multiple stimuli in a selective manner. Inspired b ...

Springer Science and Business Media LLC2025

Size‐Selective Functionalization of Sugars and Polyols Using Zeolites for Renewable Surfactant Production

Jeremy Luterbacher, Esther Amstad, Songlan Sun, Seongmin Jin

Diol functionalization with acetals in carbohydrates and polyols is ubiquitously used in protection chemistry and in the manufacture of several platform chemicals. However, the selective functionalization of molecules where multiple acetalization reactions ...

Wiley2025

Control of Buckling of Colloidal Supraparticles

Esther Amstad, Gaia De Angelis

The properties of clusters of colloidal particles, often termed supraparticles, are determined by the arrangement of the primary particles. Therefore, controlling the structure formation process is of key importance. While buckled morphologies can result f ...

Wiley2025

3D Printing of Stiff Photonic Microparticles into Load-Bearing Structures

Esther Amstad

Structural colors are bright and possess a remarkable resistance to light exposure, humidity, and temperature such that they constitute an environmentally friendly alternative to chemical pigments. Unfortunately, upscaling the production of photonic struct ...

2025

Electrostatically Reinforced Double Network Granular Hydrogels

Esther Amstad, John Martin Kolinski, Tianyu Yuan, Chenzhuo Li

Rapid advances in biomedical applications and soft robotics demand load-bearing soft materials that can be processed into complex 3D shapes. Direct ink writing (DIW) enables the fabrication of customizable shapes with locally varying compositions. Hydrogel ...

WILEY2025

Bioprinting of piezoresistive organohydrogel networks for advanced real-time mechanosensing in engineered tissue models

Esther Amstad

Understanding biomechanics in 3D cell culture is key to advancing tissue engineering, yet integrating real-time sensing into soft tissues remains a challenge. We developed a stretchable, piezoresistive hydrogel by combining PEDOT:PSS with a polyvinyl alcoh ...

2025

3D Printing of Double Network Granular Elastomers with Locally Varying Mechanical Properties

Esther Amstad

Fast advances in the design of soft actuators and robots demand for new soft materials whose mechanical properties can be changed over short length scales. Elastomers can be formulated as highly stretchable or rather stiff materials and hence, are attracti ...

Wiley-V C H Verlag Gmbh2024

Confinement-Controlled Crystallization of Guanine

Esther Amstad, Chuen-Ru Li

Guanine crystals are frequently encountered in nature in the beta-polymorph to create structural colors, to enhance the vision of creatures, and for camouflage. Unfortunately, it is challenging to control the crystallization of guanine in aqueous condition ...

Amer Chemical Soc2024

Localized Ionic Reinforcement of Double Network Granular Hydrogels

Esther Amstad, Alexandra Thoma

Nature produces soft materials with fascinating combinations of mechanical properties. For example, the mussel byssus embodies a combination of stiffness and toughness, a feature that is unmatched by synthetic hydrogels. Key to enabling these excellent mec ...

Wiley-V C H Verlag Gmbh2024

Bio-Informed Porous Mineral-Based Composites

Esther Amstad, Ran Zhao

Certain biominerals, such as sea sponges and echinoderm skeletons, display a fascinating combination of mechanical properties and adaptability due to the well-defined structures spanning various length scales. These materials often possess high density nor ...

WILEY-V C H VERLAG GMBH2024

Influence of the hydrophile-lipophile balance of perfluorinated surfactants on the emulsion stability

Esther Amstad, Gaia De Angelis

Emulsions are omnipresent in our everyday life; for example, in food, certain drug and cosmetic formulations, agriculture, and as paints. Moreover, they are frequently used to perform high-throughput screening assays with minimum sample volumes. Key to the ...

Springer Heidelberg2024

Osmosis-driven stiffening of structured hydrogels

Esther Amstad, Ran Zhao, Alexandra Thoma

Plant cells harness osmotic pressures to stiffen their leaves through strong turgor pressures. Key to this osmosisdriven stiffening is the confinement of liquids within semipermeable membranes that can regulate the transport of water molecules and ions. In ...

Elsevier2024

3D Printable κ‐Carrageenan‐Based Granular Hydrogels

Esther Amstad, Francesca Bono

𝜿-carrageenan, an algae-extracted polysaccharide known for its emulsifying properties, is widely used in food and beauty products. Because of its abundance in nature, similarity to natural glycosaminoglycans, and biocompatibility, it is a promising alterna ...

Wiley2024

Recyclable 3D printable single network granular hydrogels

Esther Amstad, Lorenzo Lucherini, Gaia De Angelis

Spherical microgels can be conveniently direct ink written into granular hydrogels because of their rheological properties when jammed. Yet, due to weak interparticle interactions, the resulting granular hydrogels are soft and often disassemble if immersed ...

2024

Integrated Conversion of Lignocellulosic Biomass to Bio-Based Amphiphiles using a Functionalization-Defunctionalization Approach

Jeremy Luterbacher, Esther Amstad, Graham Reid Dick, Stefania Bertella, Songlan Sun, Gaia De Angelis

Concerns over the sustainability and end-of-life properties of fossil-derived surfactants have driven interest in bio-based alternatives. Lignocellulosic biomass with its polar functional groups is an obvious feedstock for surfactant production but its use ...

Wiley-VCH Verlag GmbH2023

Single emulsion drops for photocatalytic water splitting as a membrane-free approach to product separation

Sophia Haussener, Esther Amstad, Swarnava Nandy, Sangram Ashok Savant, Gaia De Angelis

The coevolution of hydrogen and oxygen during photocatalytic water splitting presents a challenge for efficient product separation. Here, we demonstrate membrane-free, drop-based photocatalytic water splitting with inherent product separation and competiti ...

2023