Our gastrointestinal system is lined with thick mucus as a barrier to prevent dangerous substances from getting inside. This is why some medicines—insulin, for example—must be injected instead of swallowed. Now though, MIT researchers have developed a robotic pill that literally drills through that mucus and delivers drugs right where they're needed most. The researchers tested the RoboCapsule on pigs, loading the device with insulin and also an IV antibiotic. From IEEE Spectrum:
The entire pill is coated with a gelatinous substance that responds to pH, allowing easy swallowing and activation only upon reaching the small intestine. Once there, the coating dissolves, closing the pill's circuit and triggering its mechanical components. On one side of the pill is a weight attached to an internal motor, which makes the pill start to vibrate and spin as the motor is activated. RoboCap begins drilling through the mucus that lines the small intestine, eventually depositing its drug load, which is on the other side of the pill.
To effectively drill through the mucus, the pill uses surface features like spiral turbine fins, inspired by torpedo fins, and helical grooves. It's also coated with small studs to help "brush" mucus aside, similar to how a toothbrush works. [Lead researcher Shriya] Srinivasan said she was also inspired by online videos of tunnel-boring machines called moles, which push through rock and dirt to drill narrow channels.
