Ultra-soft atomic force microscope (USAFM) technology using nano-cantilevers for

Yazdanpanah, Mehdi

Abstract

NaugaNeedles LLC in collaboration with researchers from Purdue University are proposing to develop an advanced new Ultra-Soft Atomic Force Microscope (USAFM). This USAFM can gently create images of soft biological samples in buffer solutions with sub-picoNewton (pN) forces and sub-nm lateral resolution. This new AFM technology will have a high-bandwidth to ensure compatibility with high speed scanners. The USAFM requires development of (1) a new, small mass, ultra-soft, yet high frequency cantilevers with sharp tips and (2) an advanced motion detector instrumentation to detect ultra-soft cantilever motions. The key is to significantly decrease the cantilever's mass, which will consequently increase its resonance frequency and decrease its thermal vibration at low frequencies. Metallic silver-gallium (Ag2Ga) nano- cantilevers produced by NaugaNeedles are Ideal candidates for ultra-sensitive cantilevers since (a) they are orders of magnitude smaller than conventional cantilevers, (b) have approximately two orders of magnitude softer (k~10-4 N/m) bending stiffness, and (c) have a resonance frequencies of approximately 1-2 orders of magnitude higher than the softest commercially available cantilevers. Since this new AFM technology will have a high-bandwidth it will be compatible with high speed scanners. To demonstrate the feasibility of the USAFM, Phase I has three specific aims: 1. Fabrication of ultra-soft probes (USPs): Silver-gallium (Ag2Ga) crystalline nano- cantilevers will be fabricated in various lengths (5 to 50

Public Health Relevance

The focus of this proposal is to develop an ultra-soft atomic force microscope (USAFM). The USAFM can gently create images of soft biological samples with molecular resolution in liquid environments. This is done by applying sub-picoNewton (pN) forces to the molecules. To successfully develop a USAFM NaugaNeedles should first develop (1) a new, small mass, ultra-soft, yet high frequency cantilevers with sharp tips and (2) an advanced motion detector instrumentation to detect ultra-soft cantilever motions. This new and enhanced AFM technology will have a high-bandwidth, ensuring its compatibility with high speed scanners.