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US-12624239-B2 - Highly conductive and bioactive photosensitive resins for development of functional and hybrid electronics and sensors

US12624239B2US 12624239 B2US12624239 B2US 12624239B2US-12624239-B2

Abstract

The present disclosure describes a new resin which can be fabricated into conductive and bioactive microstructures via two-photon polymerization. The direct incorporation of conductive poly (3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) and/or multi-walled carbon nanotubes (MWCNTs) in a poly(ethylene glycol) diacrylate (PEGDA)-based blend remarkably enhances the electrical conductivity of microstructures over 10 orders of magnitude. Including biomaterials in the resin can promote cellular adhesion and create functional biosensors made of hybrid non-conductive and conductive structures for sensitive detection. Applications include development cost effective microelectronics in a broad range of biomedical research, electronics and sensors.

Inventors

  • Mohammad Reza Abidian
  • Omid DADRAS-TOUSSI
  • Milad KHORRAMI
  • Sheereen Majd

Assignees

  • UNIVERSITY OF HOUSTON SYSTEM

Dates

Publication Date
20260512
Application Date
20220916

Claims (19)

  1. 1 . A two-photon polymerization (TPP) compatible photosensitive ink or resin, wherein said ink or resin comprises at least one organic semiconductor, crosslinker, photoinitiator, and solvent: (a) wherein the at least one organic semiconductor is poly (3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) present at 0.1%-0.5% wt, the crosslinker is polyethylene glycol diacrylate (PEGDA), and the solvent is DMSO present at 25%-35% wt; or (b) wherein the ink or resin comprises two organic semiconductions comprising poly (3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) and multi-walled carbon nanotubes (MWCNTs).
  2. 2 . The ink or resin of claim 1 , wherein the ink or resin comprises two organic semiconductors comprising poly (3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) and multi-walled carbon nanotubes (MWCNTs).
  3. 3 . The ink or resin of claim 1 , wherein the photoinitiator is ethyl (2,4,6-trimethylbenzoyl) phenylphosphinate (T-POL).
  4. 4 . The ink or resin of claim 1 , wherein the solvent is dimethyl sulfoxide (DMSO).
  5. 5 . The ink or resin of claim 2 , wherein the solvent for PEDOT:PSS is DMSO and the solvent for the MWCNTs is pentaerythritol tetrakis(3-mercaptopropionate) (PETMP).
  6. 6 . The ink or resin of claim 1 , wherein the ink or resin comprises one organic semiconductor and wherein the solvent is present at 25-45 wt %, the PEPDOT:PSS is present at 0.1-0.5 wt %, the crosslinker is present at 72.5-72.9 wt %, the solvent is DMSO present at 25%-35% wt, and the photoinitiator is present at 2 wt %.
  7. 7 . The ink or resin of claim 5 , wherein the PETMP is present at 18.75 wt %, DMSO is present at 24.7-24.9 wt %, the PEPDOT:PSS is present at 0.1-0.4 wt %, MWCNT is present at 0.05-0.15 wt %, the crosslinker is present at 54 wt %, and/or the photoinitiator is present at 1.95 wt %.
  8. 8 . The ink or resin of claim 1 , further comprising a biologically active agent and/or a chemical species.
  9. 9 . The ink or resin of claim 8 , wherein the biologically active agent a protein, a nucleic acid, a carbohydrate or a lipid.
  10. 10 . The ink or resin of claim 8 , wherein the bioactive agent is an extracellular protein, a growth factor, an enzyme, a neurotransmitter, a cell adhesive protein or peptide, or a glycosaminoglycan.
  11. 11 . The ink or resin of claim 8 , wherein one or more biologically active molecules is/are present at 1-300 μg ml −1 and/or 100-4000 KU ml −1 in the ink.
  12. 12 . The ink or resin of claim 8 , wherein the chemical species is an ion.
  13. 13 . The ink or resin of claim 1 , wherein the ink or resin is in the form of a homogenous liquid.
  14. 14 . The ink or resin of claim 1 , wherein the ink or resin is in the form of a solid.
  15. 15 . A fabricated device composed of the ink or resin of claim 1 .
  16. 16 . The device of claim 15 , wherein said device comprises a three-dimensional structure selected from a conductive filler, a semiconductive nanoparticle, or a magnetic particle.
  17. 17 . The device of claim 1 , wherein the device is a TPP-fabricated microdevice.
  18. 18 . The device of claim 1 , wherein the device is a micro/nanoelectronic, a battery, an optic element, a flexible electronic device, a printed circuit board, a chip-scale electronic, a chemical/biological sensor, a micro/nano electromechanical system, an organic bioelectronic, a neural interface, a neural recording and/or stimulation device, a wearable biosensor, a bioactuator, a soft robotic, a tissue engineering scaffold, or a bioprinted organ.
  19. 19 . A method of detecting an analyte in sample or subject comprising contacting said sample or subject with a device coated with a two-photon polymerization (TPP) compatible photosensitive ink or resin, wherein said ink or resin comprises at least one organic semiconductor, crosslinker, photoinitiator, and solvent and a biological molecule that binds and/or reacts with said analyte to produce a detectable event.

Description

PRIORITY CLAIM This application claims benefit of priority to U.S. Provisional Application Ser. No. 63/245,321 filed Sep. 17, 2021, the entire contents of which are hereby incorporated by reference. STATEMENT OF FEDERAL GRANT SUPPORT This invention was made with government support under grant no. R01 NS0872254 awarded by the National Institute of Health. The government has certain rights in the invention. BACKGROUND 1. Field of the Disclosure The present disclosure relates generally to the fields of material science, electronics, optics and bioscience. More particular, the disclosure relates to improved materials and methods for the fabrication of electrically conductive micro- and nanostructures with high spatial resolution. 2. Background Development of new technologies for fabrication of conductive micro/nano structures has become a demanding research topic in various research areas including microelectronics (Zhao et al., 2013), micro/nano electromechanical systems (Jayne et al., 2018; Bogue, 2013), photonics (Kabessa et al., 2016; Schell et al., 2013), biosensing (Agarwala et al., 2017), and biomedical engineering (Takenaga et al., 2015; Wang et al., 2015). Among numerous fabrication techniques such as stereolithography, digital light processing, and electron beam melting, direct laser writing (DLW) based on two-photon polymerization (TPP) stands out since it utilizes femtosecond laser beams to create three dimensional (3D) structures with complex shapes in sub-micron resolution (˜40 nm) (Sakellari et al., 2012)(Li et al., 2009; Kawata et al., 2001; Spangenberg et al., 2013). TPP lithography is hence found to be a cost-effective and straightforward technique since it is based on one-step and mask-less DLW (Sakellari et al., 2012; Li et al., 2009; Kawata et al., 2001; Niesler & Hermatschweiler, 2015). 3D micro/nano structures fabricated by TPP technique can be hugely employed in numerous applications such as microfluidics, bioelectronics, and energy storage devices as the photo-curable inks can be tuned in terms of mechanical, thermal, optical, electrical and biological properties through being doped with a variety of functional agents such as conductive particles (Masui et al., 2011), semiconductive nanoparticles (Sun et al., 2008), magnetic materials (Xia et al., 2010), biomolecules and proteins (Carlotti & Mattoli, 2019). Significant efforts have been devoted towards electrical functionalization of TPP-compatible resins to construct conductive microdevices. Both inorganic, i.e., Au (Terzaki et al., 2011; Nakamura et al., 2019; Shukla et al., 2011) and Ag (Liu et al., 2019) nanoparticles, and organic fillers such as graphene (Oubaha et al., 2012), carbon nanotubes (CNTs) (Staudinger et al., 2017; Xiong et al., 2016; Guo et al., 2012), and organic semiconductors (conducting polymers (CPs)) (Kurselis et al., 2013) have been utilized to confer electrical properties to otherwise insulating photoresists and resultant TPP-fabricated structures (Carlotti & Mattoli, 2019). Although metallic fillers improve the electrical conductivity, refraction index of metals can interfere with the laser by creating local heat in the resin (Carlotti & Mattoli, 2019), which leads to structural deformation and reduces the quality of fabricated microstructures. Alternatively, assembly of organic fillers in TPP-compatible resins and/or TPP-fabricated structures has been a popular choice for development of next-generation microelectronic devices such as actuators, sensors, and neural microelectrodes (Xiong et al., 2016; Tao et al., 2019a), mainly due to their ease of fabrication, desirable mechanical properties, and biocompatibility. However, the range of electrical conductivity reported through incorporation of carbon-based fillers in TPP-compatible resins has remained significantly low. For example, Xiong et. al. have reported that conductivity of microstructures reached 46.8 S m−1 by incorporation of 0.2 wt % CNTs in an acrylate monomer resin (Xiong et al., 2016), indicating that achieving higher levels of conductivity is critically challenging. Organic semiconductors such as poly(3,4-ethylenedioxythiophene) (PEDOT) have attracted considerable attention due to their soft mechanical properties, mixed ionic/electronic conduction, outstanding chemical stability, biocompatibility, and ease of synthesis (Guimard et al., 2007; Long et al., 2011; Malliaras & Abidian, 2015; Antensteiner et al., 2017; Qu et al., 2016). Adjusting the doping level during fabrication allows CPs to exhibit a broad spectrum of electrical conductivity from semiconductors to metals (Green & Abidian, 2015). CPs have therefore been employed in a variety of applications including transistors and energy storage, photovoltaic cells, chemical and biological sensors (Jang, 2006), and biomedical engineering, particularly in neural prosthetics and interfaces (Ludwig et al., 2006; Abidian & Martin, 2009; Abidian et al., 2009) (Abidian et al., 2010; Abidian et al., 2006