Electrically Switchable Monostable Actuatoric Polymer-Based Nanovalve Arrays with a Long-Term Stability

Abstract

Here we present a novel electrically switchable nanovalve array based on an intrinsic conductive polymer that has the capabilities to change its volume depending on its redox state. The polymer is created by anodic deposition of a sodium dodecylbenzenesulfonate (DBS)-doped polypyrrole (PPy). Optimization of the DBS-doped PPy layers revealed an actuatoric performance of up to 10% out of plane volume change. More interestingly, the electrochemical characterization revealed an actuatoric monostable polymer that could be used to fabricate nanovalve arrays that have a native opened state when no potential is applied and that can be closed when a reductive potential is applied. As a proof of concept, Atto488-labeled biotin (Biotin-Atto488) was used as a model compound and defined nanovalve arrays with nanopores in the range of 10 nm in diameter (opened state) were fabricated. Afterward, we were able to successfully prove the functionality of our nanovalve array by monitoring the flow-through rates of the Biotin-Atto488. More strikingly, we could demonstrate for the first time the robust and long-term stability of our nanovalve array without any performance loss for at least 72 h and retention capabilities of up to 90%. Furthermore, the demonstrated long-term stability was achieved under biocompatible conditions without the need of toxic dopant supplementation of the flow-through solution. Thus, our novel functional long-term stable nanovalve array offers the capabilities for practical applications.

Polypyrrole Nanomaterials: Structure, Preparation and Application

“…Therefore, it can be used as an actuator. This kind of material can be miniaturized for component design, making it a microelectronic mechanical system device that is widely used in microrobots, microvalves, biomedical electronic devices and other fields [ 247 , 248 , 249 , 250 , 251 , 252 ].…”

Investigating volume change and ion transport in conjugated polymers

“…For example, nanoporous aluminum oxide substrates with polypyrrole as electrochemically volume changing material have been explored to control the flow of fluorescently labelled biotin and bovine serum albumin [84,85] . The latter with drug delivery applications in mind [85] .…”

An Electroactive Filter with Tunable Porosity Based on Glycolated Polythiophene

“…Volume changes of CPs have been mainly used in actuators and drug delivery devices, [16,17] while their application in smart filters is barely explored. [18][19][20] Prönnecke et al [20] demonstrated Polypyrrole-dodecylbenzenesulfonate (PPy-DBS)/Al 2 O 3 -based nanoporous filters where the flow rate of biotin could be decreased by 90% when PPy-DBS was electrochemically addressed and the porosity of the filter decreased. In another example, Tan et al demonstrated active PPy-DBS/PVDF ultrafiltration membranes.…”