A mechano-gated ionic diode enables low-power synaptic tactile spiking.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41370387.
- Also identified by DOI 10.1126/sciadv.aea5656 and PMC identifier 12694019.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Ionic diodes, which enable unidirectional ion transport, hold great promise for adaptive and energy-efficient ionotronic systems. However, conventional designs often rely on high ion concentrations, which promote ion pairing and clustering, thereby reducing mobility and impeding the formation of stable ion depletion layers (IDLs). Here, we report a mechano-gated ionic diode with balanced ionic conductivity between cationic and anionic polymer layers, achieved through copolymer engineering. This conductivity matching enables the formation of well-defined IDLs, yielding a record-high rectification ratio of 23.5 and pressure-sensitive piezo-ionic behavior. The device transduces mechanical stimuli into discrete ionic spikes via threshold-gated current modulation, consuming only 0.41 nanojoules per spike at rest and 1.49 nanojoules under pressure, achieving up to a 24-fold enhancement in signal-to-noise ratio. When integrated into a tactile interface, the diode exhibits synaptic-like plasticity and activity-dependent signal encoding. These findings establish a material-driven strategy for real-time, low-power ionic sensing and neuromorphic functionality.