In　sensory　neurons　of　mammals,　some　temperature-sensitive　transient　receptor　potential　(thermoTRP)　ion　channels　open　its　pore　for　cations　passing　through　by　the　activation　of　a　high　ambient　temperature　above　the　threshold.　This　thermal　stimulus　promotes　the　conversion　from　intracellular　osmotic　energy　to　the　electrical　signal,　which　inspires　us　to　control　energy　output　from　nanochannel-based　osmotic　power　harvesting　systems.　Here,　temperature-gated　2D　cationic　nanochannels,　stemming　from　the　stacking　of　functionalized　montmorillonite　(MMT)　lamellae,　are　constructed　for　controllable　osmotic　energy　harvesting.　Through　electronegative　modification,　nanochannels　demonstrate　an　excellent　cation　selectivity　that　is　supported　by　both　experimental　and　theoretical　findings.　When　serving　as　a　separator　for　osmotic　power　harvesting,　cationic　nanochannel　membrane　could　deliver　an　output　power　of　approximately　150　mW　m(-2),　which　is　envisaged　to　be　boosted　by　reducing　the　membrane　resistance.　Based　on　the　temperature-gated　performance　of　nanochannels,　the　energy　output　form　osmotic　power　harvesting　system　could　be　regulated　by　alternating　temperature　switches　in　a　reversible　and　stable　manner.　The　output　power　on　the　external　load　resistance　is　doubled　under　a　mild　temperature　rise　from　30　degrees　C　to　60　degrees　C.　The　strategy　that　combines　intelligent　response　with　osmotic　power　harvesting　anticipates　wide　potentials　for　controllable　energy　utilizations.