| Magnetic molecular-level sensing and manipulation are emerging as lab-on-chip platforms. These platforms entail low-cost, low-power, high efficiency, and portable implementations. Biomaterials are usually attached to magnetic beads and used in bio-analysis applications such as sorting, counting, purification, and assembly. Some of the potential applications are 2D biological or artificial tissue assembly at the micro-scale level.;Here, we present the design and demonstration of a self-contained device for sensing and manipulating biomaterials tagged with magnetic beads. The core elements of the device consist of all-integrated programmable magnetic coil arrays for pseudo-parallel sensing and actuation, which are capable of maneuvering small (bead-bound) bio-objects individually and larger ones collaboratively. Our design does not require any external magnetic sources. It relies on the magnetic field generated by planar on-chip coil arrays. The coil arrays are selectively and dynamically controlled. Each element, composed of the coil and its logical control circuitry, can detect bio-objects in the order of 1mum diameter, or manipulate them using eight-level programmable AC or DC magnetic fields. All array sensing and actuation components are shared and multiplexed to reduce the overall imprint. The components are isolated and tuned to work at 900MHz by incorporating high-speed switching (up to 40MHz) for seamless pseudo-parallel execution.;In addition, we present a new and unique on-chip biomedical proof-of-concept application. Adopting trends in neuroscience, we employ the magnetic beads to initiate and elongate neuronal axons in vitro on-chip. This application domain will assist in better understanding and studying the process of neuroregeneration, propel future clinical applications, and provide the foundation of techniques needed to wire "neuronal circuits" using living cells. |
