An international team of researchers has advanced microrobotic technologies for use in navigating unstructured environments and improving the precision of minimally invasive surgeries. Thermally actuated thin micro-grippers for these applications were designed and tested.

The researchers fabricated four heat-powered self-folding metallic micro-grippers of differing shapes and sizes but all less than a millimeter long. Use of a closed loop-control algorithm showed that these devices effectively navigated a virtual maze at up to 3.4 body-lengths per second. Three of the designs might theoretically be able to navigate against a blood-flow of 0.3 mm/s.

Along with these techniques and demonstrations of motion control in unstructured dynamic environments, these results — while to some extent constrained to the chosen design concept — can also provide quantitative data to help designers objectively identify and exploit the aspects that are most significant for achieving desired performance.

Scientists from Johns Hopkins University, University of Twente in the Netherlands and University of Groningen in the Netherlands participated in this research, which is published in the open-access journal PLOS ONE.

Scanning electron microscope images of different shapes and sizes of micro-grippers: A) 980 μm six-finger; B) 250 μm six-finger; C) 100 μm six-finger and D) 750 μm two-finger. Source: Ongaro et al (2017)