Single-chip mechatronic microsystem for surface imaging and force response studies

Abstract

We report on a stand-alone single-chip (7 ؋ 10 mm) atomic force microscopy unit including a fully integrated array of cantilevers, each of which has an individual actuation, detection, and control unit so that standard atomic force microscopy operations can be performed by means of the chip only without any external controller. The system offers drastically reduced overall size and costs as well as increased scanning speed and can be fabricated with standard complementary metal oxide semiconductor technology with some subsequent micromachining steps to form the cantilevers. Full integration of microelectronic and micromechanical components on the same chip allows for the controlling and monitoring of all system functions. The on-chip circuitry, which includes analog signal amplification and filtering stages with offset compensation, analog-to-digital converters, a powerful digital signal processor, and an on-chip digital interface for data transmission, notably improves the overall system performance. The microsystem characterization evidenced a vertical resolution of <1 nm and a force resolution of <1 nN as shown in the measurement results. The monolithic system represents a paradigm of a mechatronic microsystem that allows for precise and fully controlled mechanical manipulation in the nanoworld.atomic force microscopy ͉ cantilever ͉ complementary metal oxide semiconductor N ew measurement, metrology, and imaging techniques have been pivotal to the rapid development of many branches of science such as materials science, microelectronics, and microbiology, to name a few. The invention of the scanning-tunneling microscope by Binning and Rohrer in 1982 (1) and, in particular, the invention of the atomic force microscope (AFM) in 1986 (2) have established a basis for many findings in various scientific areas over the last years. The AFM has evolved at an exceptional speed from a laboratory prototype to a commercial instrument (consider, e.g., Veeco Instruments, Woodbury, NY) and many other scanning probe techniques (3) have been developed, which will not be further mentioned here. The AFM has been used to measure forces during stretching of DNA strands (4) and rupture forces of single covalent bonds (5) and can be operated in liquids, which enables its use in biological applications (6-8). The AFM also can be used to perform surface manipulations such as lithographic fabrication of a transistor (9, 10) or AFM-based data storage (11,12).Commercially available AFM instruments are rather bulky and have a low throughput because of the serial nature of the involved scanning process and the limited scanning range, which renders the investigation of larger samples rather laborious. The detection of the cantilever deflection is done mostly by means of a laser, which is costly and makes the adjustment and cantilever exchange very time consuming, in particular, when operating in a vacuum environment. To overcome these limitations, AFM probes with integrated detection schemes such as capacitive (13), piezoelectric or piezore...

Controlling gold nanoparticle assembly on electron beam-reduced nitrophenyl self-assembled monolayers via electron dose

“…3a, upper region). This value is lower than the previously reported literature values for NH 2 terminated SAMs on Au surfaces (340 nN), however this can be rationalized firstly due to the use of standard pyramidal probe instead of a dedicated force mapping probe, [41] and more significantly by the fact that the NO 2 to NH 2 conversion potentially does not yield a fully converted SAM at the analysed electron dose. The NO 2 terminated regions of the sample exhibited an adhesive force of approximately 40 nN, a lower value than for the NH 2 regions and rationalised by the reduced interaction of the NO 2 group with the SiO 2 surface of the tip.…”

Self-heating in piezoresistive cantilevers

“…8,9 In general, published research on piezoresistive cantilever design has either ignored Joule heating or set a power budget that is decoupled from cantilever design. 4,6 However, many applications are limited by cantilever temperature rather than power dissipation, such as biological force measurements, 10 and the temperature increase for a given power varies with cantilever design. This letter considers how the temperature-dependence of piezoresistive cantilever performance can be included in cantilever design and operation.…”

Availability of Feature-Oriented Scanning Probe Microscopy for Remote-Controlled Measurements on Board a Space Laboratory or Planet Exploration Rover

“…Weight, power consumption, and overall dimensions of an SPM to be applied on board a small space probe or a light planet rover are all constraining factors in terms of design and construction Drobek et al, 2004;Parrat et al, 2005). The significant progress recently achieved in microelectromechanical systems (Hafizovic et al, 2004;Li et al, 2007) is encouraging in this regard. The miniaturization also contributes to an increase in SPM performance (Lapshin and Obyedkov, 1993) and reliability, which is important for practical use of the FOS method.…”