Micro-medical devices have found new life in medical applications, offering advanced control, precision, and safety in surgery to augment or sometimes replace surgeons. However, current medical devices’ utility is limited just as a surgeon is, with all the functionality, all but the end tool outside the patient. Many interventional procedures would benefit from having the active medical device scaled down to fit within a few hundred micrometers, to work in the confined space of the eye, vasculature, lymphatic vessels, and so on, enabling complex motion and sensing at such a scale via remote or external control by the surgeon. Due to their inherent rigidity and size, traditional robotic tools cannot be utilized to achieve the desired clinical needs, and are limited to a few hundred niche applications.

The projects presented here have been constructed to deliver micro-scale tools for some of the most challenging clinical needs in endovascular surgery and ophthalmology. Endovascular surgical intervention for aneurysm and stroke treatment requires a means to controllably orient a catheter deep within a patient’s cerebral arteries in tortuous, complex, and challenging anatomical locations. The measurement of intraocular pressure is another, for patients with artificial corneas to enable prompt, preventative treatment to avoid glaucomatous damage. The absence of controlled actuation and sensing at the sub-millimeter length scale is the leading cause of procedural failures in these medical applications.

Through a novel combination of large aspect ratio, soft-robotic structures and saline-driven micro-hydraulics, dexterous tools to translate commands of surgeons into complex motions within brain arteries are presented. High-resolution pressure sensors are combined with micro-scale needles to enable effective measurement of intraocular pressure for patients with artificial lenses. Unlike passive fundamental studies or bench-top innovations, these projects deliver clinically functional medical devices. These approaches were validated in vivo to assess their performance and the results obtained lay the foundation for an entirely new discipline of dexterous sub-milimeter scale soft robotic tools for surgical intervention and sensing.