How a Honeybee Stinger Pumps Venom Continuously With a Double-Piston Design
New footage has revealed how a honeybee stinger continuously pumps venom. The valves attached to each lancet, located inside the venom pump chamber, change shape as they slide back and forth during pumping.
Honeybee stinger valves act like collapsible pistons
During the downstroke, each valve inflates like a parachute, creating a seal through a piston-like action. This applies downward pressure inside the chamber and forces venom out. Air escapes during the upward stroke, after which the valves change shape again as they meet in the middle and push against each other.
“The valve’s unique shape is key. It acts as a collapsible piston that can be pumped in opposite directions to provide a continuous supply of poison,” said co-author Fiorella Ramírez-Esquivel of Macquarie University. “While the double-piston design adds complexity, it is key to allowing the stinger to continuously deliver venom in a compact, autonomous unit.”
The opposing motion also minimizes backflow, helping the stinger maintain venom delivery through its compact pumping system.
3D-printed model reproduced the stinger’s pumping motion
The findings were consistent with the researchers’ preliminary flow-visualization experiments. To validate their results, the team obtained micro-CT scans and used the data to create a 3D-printed scale prototype that mimicked the observed pumping behavior.
The researchers filmed the artificial pump and analyzed its motion frame by frame. The model displayed the same pumping kinematics as the biological needle, supporting the proposed explanation of how the honeybee stinger moves venom.
Future research may examine valve materials and capillary action
Future studies could investigate the valves’ material properties in greater detail. The engineered polymer valves have extremely high elasticity, which is essential for reproducing the required deformation, as well as low friction between the valves.
Researchers could also examine whether capillary action plays a role in venom transport. At the small scale of the toxin-delivery structures, capillary forces might help draw venom into the venom duct. Alternatively, the venom may need to counteract capillary action that pulls fluid upward from the surrounding tissue.
Honeybee stinger could inspire medical microfluidic devices
Earlier studies have drawn inspiration from honeybee stinger structures to design microneedles, tissue-transport devices, and drilling tools. The researchers believe this work could eventually contribute to similar medical and microfluidic applications, including artificial pumps.
Study: PNAS, 2026
DOI: 10.1073/pnas.2603916123
Source: arstechnica.com