ABSTRACT
Our brains constitute a molecular computer that is able to process enormous amounts of information with a tiny energy budget. Inspired by the energy efficiency of brains and the ever-increasing demand for miniaturised electronics, there is a drive to develop devices that mimic the dynamic character of neurons and synapses. To achieve this goal, brain-like computing is emulated with energy inefficient and complex silicon-based circuits or with mesoscale memristors, but these approaches still require large amounts of energy. For these reasons, it is important to develop new types of hardware that can mimic brain-like computation processes. In our group we follow two types of approaches and develop 1) electrically driven molecular switches that behave like synapses with the aim to realize spiking neural networks and 2) liquid-metal oscillators that behave like neurons to realize oscillatory neural networks. I will introduce a new type of molecular switch that can remember its switching history. By coupling fast electron transport to slow proton addition steps via dynamic covalent bonds, the switches can switch in a time-dependent analogue manner like synapses and mimic basic spike-rate dependent plasticity, Pavlovian (associative) learning, and emulate all Boolean logic gates. Next, I will switch gears and introduce the concepts of liquid metal alloys of Ga and In and they can be used to study oscillatory behaviour akin to spiking behaviour of neurons. By exploiting the temporal behaviour, virtual nodes can be defined so that with a single oscillator basic classification tasks can be fulfilled. These artificial synapses and oscillators are promising to develop alternative neural networks and open new ways to design electronic devices by exploiting their inherent dynamical properties.
BIOGRAPHY
Christian Nijhuis received his Ph.D. degree from University of Twente in 2006 (Cum Laude; top 5%) under the supervision of Profs Jurriaan Huskens and David Reinhoudt. In the group of Professor George M. Whitesides at Harvard University, as a postdoctoral research fellow, he developed a platform for measurements of charge transport across layers that are one molecule thick. In 2010, he received the NRF research fellowship (3 million dollar) and he joined the Department of Chemistry at the National University of Singapore and was promoted to Assoc. Prof. in 2016. In 2012, he received the NRF CRP grant to start a new program to develop plasmonic-electronic devices which entered phase II in 2017 (total funding of 14 million dollar). In 2020, he moved back to the University of Twente as Full Professor to start a new group Hybrid Materials for Opto-Electronics. He co-authored >160 peer reviewed papers, received several awards including Dean’s Chair and NUS University Young Researcher Award.
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