We report the design, analysis and characterization of a three-inductor radio-frequency identification (RFID) and transceiver (TRX) system for potential applications in individual cell tracking and monitoring. The RFID diameter is 22 µm and can be naturally internalized by living cells. Using magnetic resonant coupling, the system shows resonance shifts when the RFID is present and also when the RFID loading capacitance changes. It operates at 60 GHz with a high signal magnitude up to −50 dB and a sensitivity of 0.25. This miniaturized RFID with a high signal magnitude is a promising step toward continuous, real-time monitoring of activities at cellular levels.

Using the cavity model and the concept of the plastic-hardening modulus, a simple relationship was established between the size of an indent and the size of a semi-spherical-shell softening zone. Indentation experiments of a Cu46.25Zr45.25Al7.5Er1 bulk-metallic glass (BMG) were performed over a range of indentation loads from 500 to 4000 mN, using a Vickers indenter. The indentation hardness decreased slightly with the increase in the indentation load from 5.21 GPa at an indentation load of 500 mN to 4.66 GPa at an indentation load of 4000 mN. The evolution of shear bands underneath the indentation was studied using an interface-bonded BMG sample. Shear bands of a semi-spherical-shell shape and a line-shape were observed underneath the indentation. The dependence of the size of the shear-banding zone on the size of the indent was examined, which qualitatively supported the analytical model. The inter-banding spacing decreased with the increase in the indentation load, associated with the release of the stored strain energy.

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The rapid growth and development of technology has had significant implications for healthcare, personalized medicine, and our understanding of biology. In this work, we leverage the miniaturization of electronics to realize the first demonstration of wireless detection and communication of an electronic device inside a cell. This is a significant forward step towards a vision of non-invasive, intracellular wireless platforms for single-cell analyses. We demonstrate that a 25 $$\upmu $$ μ m wireless radio frequency identification (RFID) device can not only be taken up by a mammalian cell but can also be detected and specifically identified externally while located intracellularly. The S-parameters and power delivery efficiency of the electronic communication system is quantified before and after immersion in a biological environment; the results show distinct electrical responses for different RFID tags, allowing for classification of cells by examining the electrical output noninvasively. This versatile platform can be adapted for realization of a broad modality of sensors and actuators. This work precedes and facilitates the development of long-term intracellular real-time measurement systems for personalized medicine and furthering our understanding of intrinsic biological behaviors. It helps provide an advanced technique to better assess the long-term evolution of cellular physiology as a result of drug and disease stimuli in a way that is not feasible using current methods.

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