Researchers speak out against proposal that would bar funding for U.S. scientists working with Chinese partners or training Chinese students

Communications Physics - Pattern formation in miscible fluid systems is typically driven by reaction-diffusion processes or thermal gradients. This study demonstrates pattern formation in an...

Modeling study shows how chemistry can trigger autonomic motion in soft materials

Cells are complex chemical systems capable of sensing and responding to environmental cues by dynamically reshaping themselves, e.g., by forming arm-like protrusions such as filopodia. Recapitulating cellular behavior in artificial systems is a long-standing goal in understanding the matter-to-life transition and designing responsive soft materials. Here, we use oil-in-water emulsions that mimic cellular environmental sensing and form directional arm-like filopodia in response to external chemical cues. Our work analyzes the step-by-step process involved in the formation of artificial filopodia, and we engineer ways to direct filopodia growth through different chemical gradients. The process is driven by asymmetric surfactant partitioning across the oil–water interface, followed by ordering at the interface to form lamellar structures, which are projected out as filopodia. We observe filopodia growing away from the source of kosmotropic anions and toward the source of chaotropic anions from the Hofmeister series. Significantly, these systems also respond to amino acid gradients, similar to cells: tryptophan gradients favor growth toward the source, while lysine and arginine gradients cause growth away from the amino acid source. Our findings open new avenues for fabricating life-like materials that sense and grow in response to external signals.

Science chats with photographer Lindsey Wasson, who captured how Nobel winner Mary Brunkow reacted to life-changing news

Chemistry research is fueling Pennsylvania’s economy — so why are we defunding it?

A group of tiny particles followed “breadcrumbs” left behind by a different group of particles in new experiments demonstrating the first steps in creating intelligent communicating systems involving ...

Researchers at Penn State demonstrate the first steps in the design of tiny particles that can perform specialized tasks, such as targeted delivery of drugs or other cargo.

Scalar energy can drive formation of non-equilibrium steady-states or power directional processes such as chemotaxis, ion transport across a membrane, or walking along a polar track. This work focuses...