The brain is the most powerful computer in existence, possessing roughly 100 billion neurons with one-quadrillion synapse connections between them. Mimicking the synapse of a neuron could lead to increasing processing power, a better understanding of brain functions, or enhanced biomedical device integration. We have previously demonstrated proton-conducting devices with synaptic behaviors utilizing protons as charge carriers in a palladium source-drain system. Altering the design of these devices to become more useful to the biomedical field would be highly advantageous. Due to nature’s naturally curved geometry, we aim to develop flexible devices capable of matching these parameters for biomedical integrations. Flexible devices allow a much broader scope of applications, including health sensors on the human body that might require soft or curved morphologies. The mechanical engineering and processing conditions to create flexible devices is currently being investigated. I propose starting device fabrication with a pre-strained substrate. When palladium is deposited on this substrate, it will compress and exhibit wave-like patterning upon the release of the substrate’s strain. This is critical to the device flexibility, as previous palladium tension tests showed a high fracture rate. With a pre-induced compression in the palladium, tension would result in a more relaxed state and limit fracture in the devices to allow flexibility. Future works involve determining buckling strains for various palladium thicknesses to obtain wave-like patterns of compression, determining a suitable substrate material, and comparison of electrical properties to our current palladium devices.

Biological systems coordinate themselves through cues such as ion currents and membrane electric potentials. This communication utilizing membrane proteins such as membrane receptors, channels, and pumps allows biological systems to form hierarchies of control over their systems that have yet to be achieved in conventional electronic systems. Integrating such biological components with nanoelectronics could allow exciting new developments in the field of biomimetic energy conversion. However, this approach requires the seamless incorporation of biological structures into electronics. In order to use membrane proteins, they must be integrated with a lipid bilayer which is essential to create a cell membrane mimicking environment. Lipid bilayers have previously been integrated on solid substrates for electrophysiological measurements and the construction of organic-inorganic hybrid devices, but have yet to be formed on PdH_x. In this work, we build the foundation towards harnessing this biology-based method of control by forming a lipid bilayer composed of DPhPC/DPhPE/PI/Cholesterol on PdH_x contacts. The formation and deposition of electrochemically robust liposomes on a PdH_x surface was confirmed using dynamic light scattering (DLS) measurements, atomic force microscopy (AFM), and resistance measurements with a PdH_x proton field effect transistor (H⁺-FET). Vesicle formation was proven through DLS by determining size of the lipid structures in aqueous solutions. These vesicles were then deposited onto a PdH_x contact and formed solid-supported bilayers on PdH_x surfaces by the process of spontaneous vesicle adsorption and rupture as confirmed by AFM. Finally, the electrical stability of the bi-lipid membrane was characterized through electrical measurements with an H⁺-FET, confirming minimal H⁺ leakage across the bilayer. Future work includes embedding an ion pumping membrane protein, bacteriorhodopsin, into the bi-lipid membrane to enable electrochemical gating of the PdH_x H⁺-FET through optical or other environmental cues for biomimetic energy conversion.