Researchers at the University of Maryland (UMD) are working to create first-of-a-kind microelectronic devices that can communicate with biological systems in ways that could have revolutionary impacts on the design of electronic devices and computing systems and on the diagnosis and treatment of disease.
“Devices that freely exchange information between the electronic and biological worlds would represent a completely new societal paradigm,” said William E. Bentley, UMD Fischell Department of Bioengineering professor, director of UMD’s Robert E. Fischell Institute for Biomedical Devices and the project’s principal investigator. “It has only been about 60 years since the implantable pacemaker and defibrillator proved what devices could achieve by electronically stimulating ion currents. Imagine what we could do by transferring all the knowledge contained in our molecular space, by tapping into and controlling molecules such as glucose, hormones, DNA, proteins, or polysaccharides in addition to ions.”
The past two decades have produced many advances in microelectronics and in synthetic biology, which can be defined as the use of electrical engineering principles to design and build into living cells the ability to perceive and process information as well as perform desired functions. But, despite these advances, there remains a basic technology gap between microelectronics and the biological world. As a result, today’s consumers cannot yet turn to their smartphones to uncover information about an infection or illness affecting their body, nor can they use them to signal a device to administer an antibiotic or drug.
Microelectronics are based on the generation and flow of free electrons through materials such as silicon, gold, or chemicals. However, because free electrons do not exist in biological systems, scientists face a major roadblock in bridging the gap between these different systems.
But, Bentley and his team have found a loophole.
In biological systems, there is a small class of molecules capable of shuttling electrons. These molecules, known as “redox” molecules, can transport electrons to any location. But, redox molecules must first undergo a series of chemical reactions – oxidation or reduction reactions – to transport electrons to the intended target.
By engineering cells with synthetic biology components, the research team has experimentally demonstrated a proof-of-concept device enabling robust and reliable information exchange between electrical and biological (molecular) domains.
Even more, the research group is now working to develop a novel biological memory device that can be written to and read from via either biological and/or electronic means. Such a device would function like a thumb drive or SD card, using molecular signals to store key information and requiring almost no energy. Inside the body, these devices would serve the same purpose – except, instead of merely storing data, they could be used to control certain biological functions.
“For years, microelectronic circuits have had limited capabilities in maximizing their computing and storage capacities, mainly due to the physical constraints that the building-block inorganic materials – such as silicon – imposed upon them,” said UMD team member Reza Ghodssi, the Herbert Rabin Distinguished Chair in Engineering, with affiliations in the Department of Electrical and Computer Engineering and the Institute for Systems Research. “By exploring and utilizing the world of biology through an integrated and robust interface technology with the semiconductor processing, we expect to address those limitations by allowing our researchers and students to design and develop first-of-kind innovative and powerful bioelectronic devices and systems.”
In addition to Bentley and Ghodssi, other team members include UMD Professor Gregory Payne, Institute for Bioscience and Biotechnology Research; Assistant Professor Massimiliano Pierobon, University of Nebraska-Lincoln’s Department of Computer Science and Engineering; and Biotechnology Scientist Jessica Terrell, U.S. Army Research Laboratory.
The research team will work to integrate subsystems and create biohybrid circuits to develop an electronically controlled device for the body that interprets molecular information, computes desired outcomes, and electronically actuates cells, allowing external signaling and control of biological populations. The group’s hope is that such a system, for example, could seek out and destroy a bacterial pathogen by recognizing the pathogen’s secreted signaling molecules and synthesizing a toxin specific to that pathogen. Through this work, the group will, for the first time, explore electronic control of complex biological behaviors.
The SemiSynBio program, a partnership between the NSF and the Semiconductor Research Corporation(SRC), seeks to lay the groundwork for future information storage systems at the intersection of biology, physics, chemistry, computer science, materials science and engineering. The program builds on many years of NSF support for basic research in synthetic biology.
This year’s SemiSynBio awards address a range of potential applications, including storing data by using DNA, automating the design of genetic circuits, creating bioelectronics and exploring methods for molecular communication.Bentley’s group is one of eight new SemiSynBio projects to receive awards this year. Additional information is available online.
According to Bentley, the new NSF SemiSynBio grant will allow the UMD-led team to continue advancing work done with the support of a Defense Threat Reduction Agency grant, a NSF Designing Materials to Revolutionize and Engineer our Future grant, and a National Institute of Biomedical Imaging and Bioengineering (NIBIB) grant.