Advantages
- Can be integrated into existing robots
- Allows easy and continuous growth underground
- Inexpensive and noninvasive approach to burrowing
- Possible to grow greater than 100% in length
Although robots have been successfully developed to recreate movement through the above-ground environment, subterranean locomotion remains a challenging endeavor. Part of this challenge is a result of the substantial forces underground resisting forward movement. A majority of current research on subterranean locomotion has centered on the field of conventional drilling. While such a method is effective at creating holes and tunnels through soil and rock it is not ideal for small subterranean robots due to the power and heavy equipment required. Burrowing animals and plant roots have inspired several recent attempts to create robots capable of subterranean locomotion however few robots can successfully maneuver through the ground.
Researchers at the University of California, Santa Barbara have created a soft robot that can successfully burrow through sand and dirt, similar to a plant root. Through extension from the top of the body, this robot can substantially increase in length from its original size and can actively control growth direction making it possible to move through tightly constrained environments typically associated with subterranean locomotion. Because lengthening from the tip involves no relative movement of the body with respect to the environment, the body can lengthen along constrained paths without friction. This robot is perfectly suited to assist in search and rescue efforts where exploration of underground areas is imperative. It can also be used to deliver fluids too hard to reach areas. Its burrowing characteristic can be applied to above-ground situations as well, such as the cleaning or inspection of difficult-to-reach spaces in complex machinery.