Seanbiron Johnson
MIT Department: Mechanical Engineering
Faculty Mentor: Prof. Ritu Raman
Research Supervisor: Ronald Heisser, Maheera Bawa
Undergraduate Institution: University of California, Berkeley
Website:
Biography
Seanbiron Johnson is an incoming sophomore at UC Berkeley, studying Mechanical Engineering & Public Policy, with a tenacious passion for biomechanics research, social justice and doctoral school. As a 2025 MIT MSRP intern, Seanbiron is conducting research in the Raman Laboratory on opto genetic stimulation of skeletal muscle tissue actuators—work with key implications for disease modeling, regenerative medicine, and soft robotics. Motivated by healthcare disparities his family faces, he is committed to research that serves communities historically neglected by the medical system. Social justice is imperative to him, because he understands that opportunity is privilege and that systematic barriers have hindered people in his hometown (Fontana, CA) from educational opportunities. At UC Berkeley, he is engaged in the Biomechanics Laboratory, EnableTech, BESSA, and the Haas Public ServiceLeaders Program. In these organizations, he helps design assistive technology, serves his NSBE Chapter, and leads a social impact project that supports educational exposure for youth.
Abstract
Optogenetic Stimulation for 2D Cantilever Skeletal Muscle Tissue Actuators, Biohybrid Robots
Seanbiron Johnson1, Maheera Bawa2, and Professor Ritu Raman2
1Department of Mechanical Engineering, University of California, Berkeley
2Department of Mechanical Engineering, Massachusetts Institute of Technology
Biohybrid robots that integrate living cells with synthetic platforms offer a promising approach for developing adaptive soft robots, regenerative therapeutics, and disease models. With that said, there are many parallels between traditional robots and biohybrid systems. The most notable parallels are the presence of sensing, actuation, and control mechanisms. In previously studied biohybrid systems, stimulation has been achieved through both optogenetic and electrical methods. However, biohybrid robots still lack limb controllability to this day. My project focuses on developing a two-dimensional cantilever skeletal muscle tissue actuator controlled through optogenetic stimulation, for localized limb control and directional movement. C2C12 mouse myoblasts, seeded on gelatin methacryloyl (GelMA) hydrogels, are genetically reengineered with the bacterial protein, Channelrhodopsin-2. This is a photosensitive protein that enables muscle contraction in response to blue light at 470 nanometers. Our actuator design has four limbs shaped in a cross-sectional configuration. To achieve reliable and localized control of these contractions, I designed and programmed a custom Arduino-based optogenetic stimulator. The optogenetic stimulator is capable of delivering light pulses to targeted muscle regions. This control is operated through a light guide and C++ code triggering any combination of the four limbs simultaneously, with a light intensity between 3mW/mm^2- 5mW/mm^2. By using this hypothesized biomechanics control technique, this work will contribute to high-precision muscle actuation platforms, regenerative therapeutics, and disease modeling.