title: Ultraminiaturized photovoltaic and radio frequency powered optoelectronic systems for wireless optogenetics.
abstract: OBJECTIVE
  Wireless control and power harvesting systems that operate injectable, cellular-scale optoelectronic components provide important demonstrated capabilities in neuromodulatory techniques such as optogenetics. Here, we report a radio frequency (RF) control/harvesting device that offers dramatically reduced size, decreased weight and improved efficiency compared to previously reported technologies. Combined use of this platform with ultrathin, multijunction, high efficiency solar cells allows for hundred-fold reduction of transmitted RF power, which greatly enhances the wireless coverage.
  
  
  METHODS
  Fabrication involves separate construction of the harvester and the injectable µ-ILEDs. To test whether the presence of the implantable device alters behavior, we implanted one group of wild type mice and compared sociability behavior to unaltered controls. Social interaction experiments followed protocols defined by Silverman et al. with minor modifications.
  
  
  RESULTS
  The results presented here demonstrate that miniaturized RF harvesters, and RF control strategies with photovoltaic harvesters can, when combined with injectable µ-ILEDs, offer versatile capabilities in optogenetics. Experimental and modeling studies establish a range of effective operating conditions for these two approaches. Optogenetics studies with social groups of mice demonstrate the utility of these systems.
  
  
  CONCLUSIONS
  The addition of miniaturized, high performance photovoltaic cells significantly expands the operating range and reduces the required RF power. The platform can offer capabilities to modulate signaling path in the brain region of freely-behaving animals. These suggest its potential for widespread use in neuroscience.
authors.affiliation: Department of Materials Science and Engineering, Beckman Institute for Advanced Science and Technology, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801.
authors.forename: Sung Il
authors.initials: SI
authors.lastname: Park
authors.affiliation: Department of Materials Science and Engineering, Beckman Institute for Advanced Science and Technology, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801.
authors.forename: Gunchul
authors.initials: G
authors.lastname: Shin
authors.affiliation: Department of Materials Science and Engineering, Beckman Institute for Advanced Science and Technology, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801.
authors.forename: Anthony
authors.initials: A
authors.lastname: Banks
authors.affiliation: Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri, 63130 USA.
authors.forename: Jordan G
authors.initials: JG
authors.lastname: McCall
authors.affiliation: Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri, 63130 USA.
authors.forename: Edward R
authors.initials: ER
authors.lastname: Siuda
authors.affiliation: Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri, 63130 USA.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Schmidt
authors.affiliation: Department of Electrical Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801.
authors.forename: Ha Uk
authors.initials: HU
authors.lastname: Chung
authors.affiliation: Department of Electrical Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801.
authors.forename: Kyung Nim
authors.initials: KN
authors.lastname: Noh
authors.affiliation: Center for Nutrition, Learning and Memory, and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801.
authors.forename: Jonathan Guo-Han
authors.initials: JG
authors.lastname: Mun
authors.affiliation: Center for Nutrition, Learning and Memory, and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801.
authors.forename: Justin
authors.initials: J
authors.lastname: Rhodes
authors.affiliation: Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri, 63130 USA.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Bruchas
authors.affiliation: Department of Materials Science and Engineering, Beckman Institute for Advanced Science and Technology, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801.|Department of Electrical Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801.
authors.forename: John A
authors.initials: JA
authors.lastname: Rogers
mesh_terms: D000818:Animals; D001921:Brain / Q000502:physiology; D017076:Computer-Aided Design; D011211:Electric Power Supplies; D004735:Energy Transfer; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D008029:Lighting / Q000295:instrumentation*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008904:Miniaturization; D062308:Optogenetics / Q000295:instrumentation*; D010775:Photic Stimulation / Q000295:instrumentation*; D011846:Radio Waves; D012666:Semiconductors; D059015:Wireless Technology / Q000295:instrumentation*