A Semiconducting Two‐Dimensional Polymer as an Organic Electrochemical Transistor Active Layer

Our work "A Semiconducting Two‐Dimensional Polymer as an Organic Electrochemical Transistor Active Layer" was published in Advanced Materials. Congratualtions to Reem Rashid for leading this effort with Austin Evans from Will Dichtel's group. This work involved a multi-group collaboration with the Marder, D'Allesandro, and Dichtel's groups.

Typical OMIECs are linear polymers, where defined and controlled microstructure/morphology, and reliable characterization of transport and charging can be elusive. Semiconducting two-dimensional polymers (2DPs) present a new avenue in OMIEC materials development, enabling electronic transport along with precise control of well-defined channels ideal for ion transport/intercalation. In this work we use a recently reported 2DP, TIIP, and patterned at 10 µm resolution as the channel of a transistor. Operating in an aqueous electrolyte, the 2DP-OECT exhibits a device-scale hole mobility of 0.05 cm2 V–1 s–1 and a µC* figure of merit of 1.75 F cm–1 V–1 s–1. 2DP OMIECs thus offer new synthetic degrees of freedom to control OECT performance and may enable additional opportunities such as ion selectivity or improved stability through reduced morphological modulation during device operation.

Nicholas Callanta
Chemical Reviews paper on Operando OMIEC characterization is out!

Grad Student Ruiheng Wu led an opus “Operando Characterization of Organic Mixed Ionic/Electronic Conducting Materials” now out in Chemical Reviews as part of a special issue on “Organic Bioelectronics”. Congrats Ruiheng, Bryan Paulsen, and a special thank you to Micaela Matta (King’s College, London).

This review provides a broad survey of operando techniques used to study OMIECs. In some cases, we highlight techniques that could provide useful insights but have not yet been demonstrated with OMIECs due to barriers to implementation. Micaela also delves into computational approaches that have been applied to OMIECs. It's important to consider these in silico methods in our in situ/operando toolbox working side by side with experimental tools.

Nicholas Callanta
3D Printed conducting hydrogels published in Macromolecular Bioscience

Our ongoing collaborative work with Cheng Sun’s lab at Northwestern is out now in Macromolecular Bioscience https://onlinelibrary.wiley.com/doi/full/10.1002/mabi.202200103

“3D-Printed Electroactive Hydrogel Architectures with Sub-100 µm Resolution Promote Myoblast Viability.” Congratulations to Rebecca Keate on leading this effort, as well as Josh Tropp, Anthony Petty, and the Sun group.

Nicholas Callanta
DARPA project for implantable ‘living pharmacy’ that would help regulate body’s sleep/wake cycles kicks off!

Our lab has received a cooperative agreement with DARPA to develop a wireless, fully implantable ‘living pharmacy’ device that could help regulate human sleep patterns. The project is through DARPA’s BTO (biotechnology office)’s Advanced Acclimation and Protection Tool for Environmental Readiness (ADAPTER) program, meant to address physical challenges of travel, such as jetlag and fatigue.

The device, called NTRAIN (Normalizing Timing of Rhythms Across Internal Networks of Circadian Clocks), would control the body’s circadian clock, reducing the time it takes for a person to recover from disrupted sleep/wake cycles by as much as half the usual time.

The project spans 5 institutions including Northwestern, Rice University, Carnegie Mellon, University of Minnesota, and Blackrock Neurotech.

See coverage on this exciting program at:

·         Northwestern

·         WGN

·         Smithsonian Magazine’s website

Nicholas Callanta
Xudong's Nature Communications paper featured in Northwestern Now!
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Researchers have developed a brain-like computing device that is capable of learning by association. 

Similar to how famed physiologist Ivan Pavlov conditioned dogs to associate a bell with food, researchers at Northwestern University and the University of Hong Kong successfully conditioned their circuit to associate light with pressure. 

The research was published today (April 30) in the journal Nature Communications. 

Read more about the study here.

Great job, Xudong!

Nicholas Callanta
Professor Rivany was named an ACS PMSE Young Investigator!

The goal of this annual symposium is to highlight and provide a forum for ~15 early-career emerging leaders who have made significant contributions in their respective fields within polymer materials science and engineering. Example research areas include synthesis, processing, characterization, physics, and engineering of macromolecular materials.

Read more here

Nicholas Callanta
Congratulations to Rebecca for being selected for the Biotechnolgy Training Program at Northwestern!

The Northwestern Predoctoral Biotechnology Training Program is an interdisciplinary and interdepartmental program that provides select graduate students (Trainees and Cluster members) greater research and training opportunities than those available through the individual departments. It promotes interdisciplinary education in biotechnology, interactions among faculty and students with interests in biotechnology, and provides a substantial exposure of students to industrial biotechnology research.

Congrats, Rebecca!

Read more about the program here

Nicholas Callanta
Bryan and Reem also have published an article in Advanced Materials!
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Our new paper is out in Advanced Materials “Energetic Control of Redox‐Active Polymers toward Safe Organic Bioelectronic Materials”. This work was led by Alex Giovannitti at Stanford, with contributions from our very own Reem and Bryan. Great collaboration with Iain McCulloch (Imperial/Kaust), Alberto Salleo (Stanford), and Jenny Nelson (Imperial) groups.

Please check it out here!

Self-aligned, laser-cut organic electrochemical transistors in Flexible and Printed Electronics

Read our latest paper in Flexible and Printed Electronics by Reem Rashid, Robert Ciechowski and Jonathan Rivnay.

In this work we introduce a new method for OECT patterning which makes use of a hydrophobic insulation layer combined with a laser cutting method that provides self-alignment of source/drain contacts, insulation and channel, and allows for the active material to be "dragged and dropped" into laser cut OECT channels. We show that this method preserves the high performance of OECTs with good reproducibility across an array.

Read more here

Nicholas Callanta