Sanctuary AI's Phoenix and the Case for Hydraulics Reborn

While much of the industry moved toward electric actuation, at least one notable platform has leaned back into hydraulics.

Sanctuary AI's Phoenix platform has used hydraulic actuation for at least some of its design, running somewhat against the broader industry trend toward fully electric actuation that companies like Boston Dynamics have followed.

The case for it

Hydraulics can still offer power density advantages electric actuation hasn't fully matched, particularly for dexterous manipulation tasks demanding significant, quickly-modulated force in a compact package — an area Sanctuary has emphasized heavily in its own positioning.

The broader takeaway

No single actuation technology has definitively 'won' across the whole industry — different companies are making different bets based on their specific target applications, and a platform's actuation choice is a genuine signal of what tasks and tradeoffs its designers are prioritizing.