lymphedema sleeve Image
Images of the lymphedema sleeve (left) and a diagram of its components (right). The microfluidic chip sequentially inflates and deflates balloons, creating pressure and pushing fluid through the arm. (Credit: Carolyn Ren)

A soft robotic sleeve controlled with a microfluidic chip reduces treatment cost, weight, and power consumption. The prototype is more portable than previous devices, and the underlying mechanisms can extend to other treatments, such as prosthetics.

The microfluidic chip has 16 channels, each acting as a sort of pipeline. Just as pipelines with different diameters create different flow speeds, the channels each have a different resistance. The differing resistances create a time delay between the flow through each channel, causing balloons in the sleeve to sequentially inflate and push fluid upwards, out of the arm.

The design requires only two miniature valves, which take the place of eight bulky, energy-consuming valves. As a result, the cost is cut from thousands to hundreds of dollars. It operates using a 3.7-V lithium-ion battery within a control box weighing less than an iPhone 13, in contrast to previous technology that required a wall outlet.