For those who came in late, 4D printing takes 3D printing a step further by using materials that can change shape over time in response to external forces.

These shape-shifting materials respond to external forces like heat, light, magnetism, or electricity, bending and twisting as needed to move payloads that traditional methods couldn’t even dream of handling.

IBM's US Patent No. 20250073998 relies on shape-memory alloys or polymers that can deform and snap back into place, like a high-tech version of those slap bracelets from the ’90s.

By carefully controlling the path and environmental conditions, IBM’s machine learning algorithm determines the exact stimulus required to flex the material and push particles forward. It’s essentially a microscopic conveyor belt that works with minimal human intervention.

IBM’s system is smart enough to detect obstacles and adjust on the fly, ensuring smooth delivery. Once the material reaches its target, all external stimuli are cut off, and the microscopic package is dropped off right on schedule.

This could be a game-changer in fields like medicine and microelectronics. In theory, doctors could use it to deliver drugs directly to specific cells through the bloodstream or gastrointestinal tract, making treatments more precise and reducing side effects.

On the industrial side, it could revolutionise semiconductor manufacturing by enabling precise particle transport in environments where human hands (or robotic arms) are too clumsy.

IBM’s new patent could allow microscopic delivery systems to handle everything from targeted cancer treatments to next-generation chip manufacturing.