Emerging transfer printing methods provide means to build a range of mechanically flexible and wearable bioelectronics, opening up a new prospect in the field of biomedical technologies. The mechanical flexibility allow the devices to intimately integrate with biological systems such as biological cells, tissues, and/or the skin at their length scale. The embedded semiconducting nanomaterials provide the electronic functionalities that can monitor and/or stimulate them with spatial and temporal controls. This presentation will talk about a novel class of transfer printing method by exploiting controlled “crack” that is capable of liberating various nanoelectronics from their native wafer over large scale. The liberated nanoelectronics can be then thinly placed onto an arbitrary surface of biological systems of interest including cells and tissues, and therefore can provide the desired electronic functionalities at the intimate interface. A multiscale computational model that incorporates atomistic debonding mechanisms into macroscale interface delamination reveals the underlying working mechanisms and provide a quantitative guidance for controllable cracking process. The knowledge obtained from these studies provides important insights to improve the manufacturability in terms of scalability, controllability, and reproducibility. System-level demonstrations include skin-mountable sensors and cell-injectable silicon nano-needles, which can validate their utility in wearable healthcare systems and intracellular drug delivery platform. Discussions about the results of detailed experimental and theoretical studies will follow to reveal the essential attributes of the materials, devices, and fabrication process.