25-06-2012, 12:47 PM
Biodegradable electronics
[attachment=25393]
Introduction
Traditional pursuits in organic electronics have demonstrated tremendous versatility in a wide range of applications including consumer electronics, photovoltaics, and biotechnology. However, the interface of biomolecules and organic semiconductors has recently explored the potential use of natural and synthetic polymers as structural components of electronic devices. The fabrication of electronically active system using biomaterials-based components has the potential to realize a large set of unique devices including environmentally biodegradable systems and bioresorbable temporary medical devices [1]
Natural organic semiconductors
There are abundant opportunities in the convergence of biodegradable materials and organic semiconductors to produce electronic systems with unique overall material profiles. Melanins are a unique class of organic material that bridges organic semiconductors and biomaterials. Melanins have demonstrated unique switching properties [2] as well as biocompatibility.[3] Carotenoids, a class of naturally occurring small molecule pigments, have been studied as potential use in organic thin-film silicon transistors, OTFTs.[4] Carotenoids are small molecule polyenes that serve as precursors for many biomolecules including Vitamin A. Bixin and beta-carotene, two specific types of carotenoids, were processed from solution to form OTFTs which exhibited hole mobilities on the order of 10−6 and 10−7 cm2-V−1-sec−1, respectively. While the electrical performance of these specific materials may not be yet suitable for particular device applications, this work demonstrates the wide range of electronic properties that biomaterials can possess.
Biomaterials-based electronic devices
One particularly intriguing concept is the notion of fabricating fully bioresorbable electronic devices for potential use in temporary electronically active medical devices. Towards this end, recent efforts have focused on the fabrication of OTFTs in a fully biodegradable platform as a proof of concept. Initial iterations of this concept utilize synthetic biodegradable polymers that are both ubiquitous in medical applications and exhibit appropriate electronic properties. Towards this end, Bettinger and Bao developed one of the first examples of a biodegradable biomaterials-based transistor. They focused on the fabrication of OTFTs in a fully biodegradable platform as a proof of concept. Initial iterations of this concept utilize synthetic biodegradable polymers that are both ubiquitous in medical applications and exhibit appropriate electronic properties.[5] Poly(DL-lactide-co-glycolide) (PLGA) was melt processed to form the device substrate, which comprises over 99% of the device by mass. Solution-processed PVA was selected as the gate dielectric because of its demonstrated advantages in electronic and biomedical applications. The active layer consisted of hydrophobic small molecule semiconductor that has previously demonstrated stable operation in aqueous environments.[6] While the biodegradation of the small molecule active layer has not been studied explicitly.
Compostable electronics
The notion of fabricating organic electronic devices on environmentally compostable material platforms is an intriguing possibility for biodegradable electronic materials. Organic electronic components have been fabricated on substrate materials such as aluminum foil [10] and paper [11] to accommodate these expanded functionalities. In one embodiment of this idea, paper films were utilized as a combination substrate and gate dielectric for use with pentacene-based active layers.[11] This idea was expanded upon to create complete circuits using foldable paper-based substrates.
1. This demonstration was motivated by two primary factors:
1. paper substrates are mechanically flexible and capable of small bending radii
2. paper is ubiquitous in modern society
As such, utilizing paper-based substrates are a potentially very important strategy for widespread deployment of simple electronic devices. A wide range of functionality is demonstrated including the ability to fabricate circuits on rolls of paper that can be easily crafted into the final form by virtue of simple folding and cutting techniques.
[attachment=25393]
Introduction
Traditional pursuits in organic electronics have demonstrated tremendous versatility in a wide range of applications including consumer electronics, photovoltaics, and biotechnology. However, the interface of biomolecules and organic semiconductors has recently explored the potential use of natural and synthetic polymers as structural components of electronic devices. The fabrication of electronically active system using biomaterials-based components has the potential to realize a large set of unique devices including environmentally biodegradable systems and bioresorbable temporary medical devices [1]
Natural organic semiconductors
There are abundant opportunities in the convergence of biodegradable materials and organic semiconductors to produce electronic systems with unique overall material profiles. Melanins are a unique class of organic material that bridges organic semiconductors and biomaterials. Melanins have demonstrated unique switching properties [2] as well as biocompatibility.[3] Carotenoids, a class of naturally occurring small molecule pigments, have been studied as potential use in organic thin-film silicon transistors, OTFTs.[4] Carotenoids are small molecule polyenes that serve as precursors for many biomolecules including Vitamin A. Bixin and beta-carotene, two specific types of carotenoids, were processed from solution to form OTFTs which exhibited hole mobilities on the order of 10−6 and 10−7 cm2-V−1-sec−1, respectively. While the electrical performance of these specific materials may not be yet suitable for particular device applications, this work demonstrates the wide range of electronic properties that biomaterials can possess.
Biomaterials-based electronic devices
One particularly intriguing concept is the notion of fabricating fully bioresorbable electronic devices for potential use in temporary electronically active medical devices. Towards this end, recent efforts have focused on the fabrication of OTFTs in a fully biodegradable platform as a proof of concept. Initial iterations of this concept utilize synthetic biodegradable polymers that are both ubiquitous in medical applications and exhibit appropriate electronic properties. Towards this end, Bettinger and Bao developed one of the first examples of a biodegradable biomaterials-based transistor. They focused on the fabrication of OTFTs in a fully biodegradable platform as a proof of concept. Initial iterations of this concept utilize synthetic biodegradable polymers that are both ubiquitous in medical applications and exhibit appropriate electronic properties.[5] Poly(DL-lactide-co-glycolide) (PLGA) was melt processed to form the device substrate, which comprises over 99% of the device by mass. Solution-processed PVA was selected as the gate dielectric because of its demonstrated advantages in electronic and biomedical applications. The active layer consisted of hydrophobic small molecule semiconductor that has previously demonstrated stable operation in aqueous environments.[6] While the biodegradation of the small molecule active layer has not been studied explicitly.
Compostable electronics
The notion of fabricating organic electronic devices on environmentally compostable material platforms is an intriguing possibility for biodegradable electronic materials. Organic electronic components have been fabricated on substrate materials such as aluminum foil [10] and paper [11] to accommodate these expanded functionalities. In one embodiment of this idea, paper films were utilized as a combination substrate and gate dielectric for use with pentacene-based active layers.[11] This idea was expanded upon to create complete circuits using foldable paper-based substrates.
1. This demonstration was motivated by two primary factors:
1. paper substrates are mechanically flexible and capable of small bending radii
2. paper is ubiquitous in modern society
As such, utilizing paper-based substrates are a potentially very important strategy for widespread deployment of simple electronic devices. A wide range of functionality is demonstrated including the ability to fabricate circuits on rolls of paper that can be easily crafted into the final form by virtue of simple folding and cutting techniques.