As humans venture in space at longer distances from Earth and for more extended periods, two needs become pressing:
- to accurately monitor crew health for better understanding the effects of space travel and colonization on health, as well as devising effective medical prevention and intervention strategies;
- to maximize material recycling in space (spaceships or settlements) so that the dependence on resupply from Earth is minimized.
The strong interrelation between those two needs is evident within the framework of space advanced life support systems (ALSS): the accurate monitoring of chemical compounds – as biomarkers – in crew metabolic wastes is essential not only for knowing the crew health status, but also for optimizing the functionality of the downstream LSS processes “feeding” on the crew metabolic wastes.
As there is currently no routine monitoring of any biomarkers in space, ESTEE, in collaboration with CSEM (the Swiss Center for Electronics and Microtechnology), is developing the SUMIT (Space Urinalysis Module for Innovative Toilet) prototype for incorporation into a space toilet (e.g., in a spaceship or at a planetary base). SUMIT is designed to accurately and automatically monitor different biomarkers in fresh urine, an ideal medium for biomarker monitoring,using miniaturized electrochemical sensors (see figure). Therefore, SUMIT is important not only for the non-invasive monitoring of crew health, but also for the overall functionality of advanced life support system (ALSS) (e.g., regulation of the urine loading to downstream processes, proper nutrition of plants and microalgae for food production and atmosphere regeneration, prevention of scaling in water recovery processes, etc.).
The miniaturized printed electrochemical sensors are considered game changers in decentralized health monitoring due to: their capacity to target different biomarkers separately or in combination and to be integrated in miniaturized devices, their low requirements for sample volume and energy, fast time to results, and low production cost.
Beyond its important space applications, SUMIT is designed for connectivity to urine-diverting toilets on Earth, and data transmission to the user’s data cloud. Therefore, SUMIT also enables home-based quantitative, accurate and affordable monitoring of urine biomarkers in a non-invasive, hygienic, and user-friendly manner.