Moisture-responsive　actuators　are　promising　for　advanced　applications,　including　biosensors　and　soft　robotics.　However,　the　fabrication　process　and　actuating　performance　need　improvement.　Here,　we　report　a　rapid　moisture-responsive　thin　film　fabricated　from　tempo-oxidized　cellulose　nanofibers　(TOCNFs)　by　direct　ink　writing　(DIW).　The　thin　film　is　lightweight　and　flexible,　and　the　resulting　actuator　exhibits　a　subsecond　response　upon　moisture　exposure.　This　rapid　actuation　is　owing　to　the　water　molecules＇　stress　differential　throughout　the　thickness　of　the　thin　film　and　their　interaction　with　the　polar　groups　in　the　thin　film　to　form　hydrogen　bonds.　This　thin　film-based　actuator　has　demonstrated　a　good　weight-lifting　capability　and　can　be　utilized　in　intelligent　lifts,　textile　layers,　and　wearable　electronics.　©　2023　IEEE.