This document summarizes research on electrically conductive hydrogel composites formed from poly(ethylene glycol) diacrylate hydrogels and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS). The composites were created by combining PEG-DA, PEDOT:PSS suspension, and a UV crosslinker, then photopolymerizing to form hydrogels containing embedded PEDOT:PSS. Testing showed the composites' mechanical properties, conductivity, and charge storage capacity could be tuned by varying the PEDOT:PSS concentration from 0-15%. Future work will investigate effects of hydration/drying cycles and different dopants on

1. Photopolymerizable Conducting Polymer-Hydrogel Composites
INTRODUCTION RESULTS
ACKNOWLEDGEMENTS
• Dr. Kenneth J. Wynne and Chenyu Wang, Chemical and Life Science Engineering, VCU for use and
help with DMA.
Benjamin Chalfant, Ramendra Pal, Emigdio Turner and Vamsi K. Yadavalli
Department of Chemical and Life Science Engineering
FUTURE WORK
• Determine long term effects of hydration and drying fatigue.
• Determine mechanical and electrical characteristics upon introduction of and other dopants.
• Use material to develop electrode coatings, patterned cell scaffolds, and biosensors.
METHODS
Optical Microscopy
Test pattern, 9.6% PEDOT Grid, 5.1%PEDOT
Atomic Force Microscopy
Surface morphology of dried film
Conductivity map of
15% PEDOT dried film
• The application of Electrically Conductive Hydrogels (ECHs) for biomedical implantation and
instrumentation is a growing field that offers a new controllable dynamic. Applications for
ECHs include in vivo and in vitro bio-sensing, neural stimulation, bioelectric signal processing and
controlled drug delivery.
• Electrically conductive composites can allow hydrogels to conduct electricity and store charge.
Composites can be formed from hydrogels and conductive polymers.
• The study shown here evaluates the electrical and mechanical characteristics of a
photopolymerizable ECH over a range of conductive polymer concentration (from 0-15 wt%).
The hydrogel is polyethylene glycol diacrylate and the conductive polymer is PEDOT:PSS
• Poly (ethylene glycol) diacrylate
(PEG-DA) and a poly (3,4-
ethylenedioxythiophene)-poly
(styrenesulfonate) (PEDOT:PSS)
suspension were combined with a UV
cross linker.
• The composite was aliquoted into
cylindrical poly (dimethylsiloxane)
(PDMS) molds, glass slides and
indium tin oxide (ITO) coated slides
for mechanical, conductive and charge
storage characterization respectively.
• UV exposure polymerized the PEG-
DA entrapping the PEDOT
suspension within the hydrogel.
• Mechanical, conductivity and charge
storage characterization were then
performed using dynamic mechanical
analysis (DMA), four point probe and
cyclic voltammetry (CV) respectively.
Suspension
placed in mold
Photopolymerized
using UV lamp
Polymerized free standing
hydrogel composite disc
Suspension of
PEDOT:PSS in water
and PEG-DA with
photo initiator
Samples in DMA instrument
0
200
400
600
800
1000
1200
11.3 16.2 28.4 48.2 48.5
Modulus (kPa)
Hydrated % PEG-DA
15 %
10 %
5%
2 %
no PEDOT:PSS
% PEG-DA % PEDOT:PSS % Hydra<on SD
48.5 0% 0 0
48.2 2% 58.1 1.8
28.4 5% 73.4 0.4
16.2 10% 89.5 0.6
11.3 15% 95.9 0.4
Average Modulus over PEG-
DA and PEDOT:PSS
concentration
% Hydration Within Hydrogel Composites
0
0.005
0.01
0.015
0.02
0.025
0.03
0.035
0.04
0.045
0.05
5 10 15 25 50
Conduc<vity (S/cm)
Dry % PEDOT
% PEDOT:PSS CSC (mC/cm2) SD
Bare ITO 0.48 0.12
0% 1.69 0.12
5% 3.83 0.43
10% 6.60 0.58
15% 19.89 0.41
Composite Conductivity over
PEDOT:PSS Concentration
Range
Charge Storage Capacity of Hydrogel Composites
CONCLUSIONS
• Composites of hydrogels with electrically conductive polymers (ECH) can be formed with various
compositions of PEG and PEDOT:PSS.
• The ECH with competitive electrical properties can be tuned to specific modulus.
• Photopolymerization of PEDOT:PSS - PEG-DA ECHs allows for microstructure fabrication.
Micropatterning of composite ECH