Tricorder Tech: Alien Carousel – In Situ Life Detection On Icy Moons With A Single-actuator Holographic Microfluidic Platform

Enceladus, one of Saturn’s moons, is considered one of the most promising places in the solar system to find life.

The Cassini mission discovered organic-rich water plumes from Enceladus’s subsurface ocean, prompting new lander mission planning. We developed a mechanically simple ice sampling system for autonomous life detection on lander missions.

The system is controlled by a single rotary actuator that samples, liquefies, and prepares ice for microscopic observations. Sample acquisition uses a novel conical boundary layer pump that delivers samples to a microfluidic disk. A digital holographic microscope detects microorganisms without mechanical focusing.

The single-actuator design enables closed-loop control of velocity, position, and torque, with an operational sequence controlling fluid dynamics in a centrifugal microfluidic disk. Testing demonstrated system feasibility and effectiveness across all subsystems. Open-source software was developed for automated onboard hologram processing, including organism motility detection to assess presence of life.

This single-actuator design reduces mechanical complexity for lander missions. Future work focuses on adapting the technology for terrestrial applications and achieving required technology readiness levels for space deployment.

Operational phases for a single sample: (a) The system is placed on an icy surface with its conical shroud touching the surface. A circular heating element brings the water phase from solid to liquid. (b) While maintaining a localized heated region, the system starts rotating. This accelerates the melted fluid towards a higher location within the disk that sits on top. (c) At a different spinning rate, the liquid that originated from the cone enters a circular channel within the disk until the channel is filled. (d) By stopping the rotation, the disk will come to a standstill. Along the full perimeter of the disk, scientific instruments can perform their analysis on the liquid. By changing the angular position of the disk in a stepwise motion, the complete channel can be analyzed by every instrument in one go. (e) By spinning at a much higher angular velocity, the capillary burst valve at the outer perimeter bursts, allowing the complete volume of liquid to be emptied. — Frontiers

Alien Carousel: In Situ life detection on icy moons with a single-actuator holographic microfluidic platform, Frontiers (open access)

Astrobiology,