Sensors: High Bandwidth and Minimally Invasive Micro-Cantilever Sensing Based on Transient Dynamics and Thermal Noise Effects

One of the most promising technologies that has evolved in the last decade that provides atomic precision is based on the micro-cantilever. Indeed, these devices were amongst the first to demonstrate the feasibility of nanotechnology. Micro-cantilever based devices have revolutionized interrogation control and manipulation of matter at the nanoscale. However, the vast potential of such devices is far from being harnessed.

In this proposal we will develop an innovative scheme where the micro-cantilever transient is effectively employed to obtain microsecond time scales for sample investigation. This new method called transient signal imaging will be several orders of magnitude faster with all the desirable features of the present dynamic mode. This will provide the first micro cantilever method of investigation of dynamics at the nanoscale with microsecond temporal resolution.

In many proposed applications of the micro-cantilever based sensing, like single electron spin detection where the aim is to detect a single electron spin at room temperature, it is imperative that the sensing does not disturb the phenomenon being observed. Another key feature of such studies is that the forces are often localized and could evolve over relatively large time scales. An innovative aspect of the proposal is a thermal noise based scheme that leads to a minimally invasive way of interrogation over relatively large time scales. The high sensitivity will be achieved by maintaining Angstrom scale tip-sample distances and by controlling the cantilever tip to be in the gentler attractive regime of the tip-sample interaction potential. This is achieved by estimating the equivalent frequency of the microcantilever from its thermal noise.

To aid the innovative methods to be developed in the proposed investigation we present a

comprehensive experimental setup which can be utilized to obtain multi-mode models of the micro-cantilever. Such an instrument is crucial to the development of the transient signal imaging and will be used to validate and suggest future strategies.

The broader impacts of this proposal are significant. Micro-cantilevers are being used in diverse areas with increasing impact and have influenced science in a fundamental manner. The two methods are enabling technologies and will open doors for investigating basic science issues by providing ultra-high bandwidth and resolution. The innovative contributions of the proposals will directly impact most aspects of scanning probe microscopy, as the proposed methods apply to most of the existing setups. The experimental aspects of the proposed research will be accomplished in collaboration with Asylum Research a leading biology related scanning probe microscope (SPM) company. This collaboration is expected to foster transfer of the theory and technology developed in this program between the academic institution of the PI and the SPM industry.