Wireless in-body sensing and actuation through genetically modified bacteria

This thesis introduces a new class of fully passive, wireless bio-hybrid implants that integrate genetically engineered bacteria with microwave resonators to enable molecular-level sensing and wireless control inside the body. Synthetic biology offers powerful tools to reprogram living cells for detecting specific target molecules; however, the lack of viable wireless communication mechanisms has limited their use in vivo. Direct electromagnetic interaction with individual cells would require THz frequencies, which are strongly attenuated in biological tissues. To overcome this, this work links cellular responses to electromagnetic signals by coupling engineered E. coli with a biodegradable passive microwave antenna. The bacteria modulate the antenna's degradation rate, and the resulting resonance shifts are wirelessly tracked using backscatter communication. This approach enables real-time, battery-free molecular sensing at an implant depth of 25 mm in muscle-mimicking phantoms. In addition, this thesis demonstrates a method for wireless thermal actuation of engineered bacteria using focused microwave hyperthermia. An on-body antenna delivers energy to the implanted resonator, producing localized heating while maintaining the temperature of surrounding tissue below the 43°C safety threshold. Multiphysics simulations show that the system can induce a localized temperature rise exceeding 6°C within 5 minutes under 1 W input power—sufficient to activate heat-inducible genetic circuits and trigger protein expression. This work represents the first demonstration of a wireless link between a passive, cell-based implant and an on-body antenna, laying the groundwork for battery-free, circuit-free cellular implants for continuous biosensing and programmable therapeutic applications.