Biomimetic Mole-bot set to drill in complex environments

The African mole-rat and European mole have inspired the development of Mole-bot, a machine expected to perform excavations in complex environments.

Developed at KAIST (Korea Advanced Institute of Science and Technology), the 25kg Mole-bot is proposed as tool for space exploration and mining for resources such as coalbed methane and Rare Earth Elements, which require highly advanced drilling technologies.

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“The crushing power of the African mole-rat’s teeth is so powerful that they can dig a hole with 48 times more power than their body weight. We used this characteristic for building the main excavation tool. And its expandable drill is designed not to collide with its forelimbs,” said Prof Hyun Myung from KAIST’s School of Electrical Engineering.

According to KAIST, the 25cm wide and 84cm long Mole-bot can excavate three times faster with six times higher directional accuracy than conventional models.

After digging, the robot removes the excavated soil and debris using its forelimbs. This embedded muscle feature, inspired by the European mole’s scapula, converts linear motion into a powerful rotational force. For directional drilling, the robot’s elongated waist changes its direction 360° like living mammals.

KAIST developed biomimetic robot ‘Mole-bot’ (Image: KAIST)

For exploring underground environments, the research team developed and applied new sensor systems and algorithms to identify the robot’s position and orientation using graph-based 3D Simultaneous Localisation and Mapping (SLAM) technology that matches the Earth’s magnetic field sequence, which enables 3D autonomous navigation underground.

According to Market & Market’s survey, the directional drilling market is expected to grow to $103bn in 2021. The growth of the drilling market is likely to expand further into the future development of space and polar resources.

The Mole-bot is claimed to be step forward for efficient underground drilling and exploration technologies. Unlike conventional drilling processes that use environmentally unfriendly mud compounds for cleaning debris, Mole-bot can mitigate environmental damage. The researchers said in a statement that their system saves on cost and labour and does not require additional pipelines or other ancillary equipment.

“We look forward to a more efficient resource exploration with this type of drilling robot. We also hope Mole-bot will have a very positive impact on the robotics market in terms of its extensive application spectra and economic feasibility,” said Prof Myung.