Biomimetic temperature-gated 2D cationic nanochannels for controllable osmotic power harvesting

Abstract 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 °C to 60 °C. The strategy that combines intelligent response with osmotic power harvesting anticipates wide potentials for controllable energy utilizations.