In Situ Observation of Low-Power Nano-Synaptic Response in Graphene Oxide Using Conductive Atomic Force Microscopy

Fei Hui, Peisong Liu, Stephen A. Hodge, Tian Carey, Chao Wen, Felice Torrisi, D. Thanuja L. Galhena, Flavia Tomarchio, Yue Lin, Enrique Moreno, Juan B. Roldan, Elad Koren, Andrea C. Ferrari, Mario Lanza

Research output: Contribution to journalArticlepeer-review


Multiple studies have reported the observation of electro-synaptic response in different metal/insulator/metal devices. However, most of them analyzed large (>1 µm2) devices that do not meet the integration density required by industry (1010 devices/mm2). Some studies emploied a scanning tunneling microscope (STM) to explore nano-synaptic response in different materials, but in this setup there is a nanogap between the insulator and one of the metallic electrodes (i.e., the STM tip), not present in real devices. Here, it is demonstrated how to use conductive atomic force microscopy to explore the presence and quality of nano-synaptic response in confined areas <50 nm2. Graphene oxide (GO) is selected due to its easy fabrication. Metal/GO/metal nano-synapses exhibit potentiation and paired pulse facilitation with low write current levels <1 µA (i.e., power consumption ≈3 µW), controllable excitatory post-synaptic currents, and long-term potentiation and depression. The results provide a new method to explore nano-synaptic plasticity at the nanoscale, and point to GO as an important candidate for the fabrication of ultrasmall (<50 nm2) electronic synapses fulfilling the integration density requirements of neuromorphic systems.

Original languageEnglish
Article number2101100
Issue number26
StatePublished - 1 Jul 2021


  • conductive atomic force microscopy
  • electronic synapses
  • graphene oxide
  • resistive switching
  • spray coating
  • synaptic plasticity

All Science Journal Classification (ASJC) codes

  • Biotechnology
  • Biomaterials
  • Chemistry(all)
  • Materials Science(all)


Dive into the research topics of 'In Situ Observation of Low-Power Nano-Synaptic Response in Graphene Oxide Using Conductive Atomic Force Microscopy'. Together they form a unique fingerprint.

Cite this