3D Matter Made to Order

From September 7–11, the HEiKA Summer Science Academy 2025 brought together master’s and final-year bachelor’s students at the Bildungshaus St. Bernhard in Rastatt. The academy was organized by the Heidelberg-Karlsruhe Strategic Partnership HEiKA in partnership with our Cluster 3DMM2O and the Flagship Initiative Engineering Molecular Systems of Heidelberg University. Participants attended hands-on workshops led by top researchers who covered topics such as biofabrication, responsive materials, stem cell dynamics, cancer evolution, and 3D lithography. The program provided a unique, immersive experience that fostered collaboration, exchange, and innovation at the intersection of molecular systems and 3D engineering.

A new study, including Cluster Doctoral Researchers Maike Schliephake and Yan Liu and PIs Prof. Dr. Jasmin Aghassi-Hagmann and Prof. Dr. Pavel Levkin, explores the use of fluorescent metal-organic framework (MOF) thin-film arrays as surface-based sensors. They created stable, easy-to-use devices by directly patterning fluorescent dyes onto flat MOF films, overcoming the drawbacks of MOF suspensions. These arrays can track pH levels within the biological range (5–9) and detect disease-related molecules, such as dopamine. Their robust design enables multiplexed measurements and integration into lab-on-a-chip systems, creating opportunities in healthcare, environmental monitoring, and food safety.

© Wang et al., Small 2025, CC BY

A new study in Communications Materials — including Cluster Postdoctoral Researcher Nils Rosemann and Principal Investigators Jasmin Aghassi-Hagmann and Stefanie Dehnen — demonstrates the first successful inkjet printing of adamantane-type organotin sulfide clusters without altering their molecular identity. These clusters exhibit unusual optical properties, producing either white light or frequency doubling depending on their structure. The researchers overcame the longstanding challenges of instability and poor solubility by combining phenyl groups, which improve optical performance, with alkyl chains, which improve solubility. This breakthrough paves the way for printable, reusable, and thermally stable optical data storage materials.

© Nier et al., Communications Materials, 2025, CC BY 4.0

A recent study, including Cluster Doctoral Researcher Alexander Berkes, Alumnus Pascal Kiefer and PI Martin Wegener, explores how the geometry of carrier particles affects drug delivery in dry powder inhalers. The team used multi-photon 3D laser printing to create millions of microparticles with different shapes and surface textures. The spiked Pharmacone design performed best, enabling the highest fraction of respirable drug particles. Although these particles are not intended for inhalation, this approach suggests the possibility of future biocompatible, precision-engineered carriers for more effective lung therapies.

© Wostry et al., Communications Materials 2025, CC BY 4.0

Scientists, including Cluster Alumna Tugce Nur Eren, Doctoral Researcher Jonathan L. G. Schneider, Postdoctoral Researcher Florian Feist, and PIs Martin Wegener, Jens Bauer, and Christopher Barner-Kowollik, have developed a single-component resin for 3D microprinting that enables structures with a wide range of mechanical properties in a single step. Unlike conventional resins, it does not require photoinitiators or additional crosslinkers. By adjusting laser power and scan speed, both very soft and flexible structures and very stiff and rigid structures can be produced. This breakthrough opens new opportunities in soft robotics, microfluidics and biofabrication.

© T. N. Eren, et al., Adv. Funct. Mater., 2025, CC BY

A new episode of our Explain Like I’m Five series is now live, exploring the fascinating world of human brain organoids. Lízia Branco, a Cluster Doctoral Researcher at the Karlsruhe Institute of Technology (KIT), demonstrates how lab-grown organoids made from stem cells can be used to study brain development and neurological disorders, eliminating the need for animal testing. Lízia combines her background in physics with neuroscience to apply imaging, data analysis, and machine learning to reveal how genetic and environmental factors influence the brain. The episode also discusses whether AI could play a role in detecting and helping to “fix” brain disorders.