Wireless flow-powered miniature robot capable of traversing tubular structures

Wireless millimeter-scale robots capable of navigating through
fluid-flowing tubular structures hold substantial potential for
inspection, maintenance, or repair use in nuclear, industrial, and medical
applications. However, prevalent reliance on external power constrains
their operational range and applicable environments. Alternatives with
onboard powering must trade off size, functionality, and operation
duration. Here, we propose a wireless millimeter-scale wheeled robot
capable of using environmental flows to power and actuate its
long-distance locomotion through complex pipelines. The flow-powering
module can convert flow energy into mechanical energy, achieving an
impeller speed of up to 9595 revolutions per minute, accompanied by an
output power density of 11.7 watts per cubic meter and an efficiency of
33.7%. A miniature gearbox module can further transmit the converted
mechanical energy into the robot’s locomotion system, allowing the robot
to move against water flow at an average rate of up to 1.05 meters per
second. The robot’s motion status (moving against/with flow or pausing)
can be switched using an external magnetic field or an onboard mechanical
regulator, contingent upon different proposed control designs.
Additionally, we design kirigami-based soft wheels for adaptive
locomotion. The robot can move against flows of various substances within
pipes featuring complex geometries and diverse materials. Solely powered
by flow, the robot can transport cylindrical payloads with a diameter of
up to 55% of the pipe’s diameter and carry devices, such as an endoscopic
camera for pipeline inspection, a wireless temperature sensor for
environmental temperature monitoring, and a leak-stopper shell for
infrastructure maintenance.