MEMS capacitive accelerometers have been widely used for consumer and automobile applications. Our purpose is high sensitivity and low noise level to measure motion precisely. We propose an arrayed structure to improve sensitivity without increasing volume. The size effect is investigated. [Applications]  seismic measurement  geophysical exploration

A sub-micron-gap SOI capacitive accelerometer array utilizing size effect

Understanding of high-temperature mechanical property is necessary for the reliability of MEMS in harsh environments. Single crystal silicon is one of standard materials in MEMS, and changes fracture behavior from brittle to ductile at high temperature. This research focuses on the size effect on BDTT (brittle-ductile transition temperature) and investigates it by means of tensile testing in vacuum with a concentrated IR heating. [Applications] Database of fracture strength of single crystal silicon Design guideline of MEMS devices with higher reliability [Publications] A. Uesugi, Y. Hirai, T. Yasutomi, T. Tsuchiya, and O. Tabata, Jpn. J. Appl. Phys., 2015, accepted. A. Uesugi, Y. Hirai, T. Tsuchiya, and O. Tabata, The 28th IEEE International Conference on Micro Electro Mechanical Systems, MEMS2015.

High-temperature mechanical property of single crystal silicon microstructures

Silicon is a standard material of MEMS. Since MEMS devices need mechanical deformations for their operations, evaluation of its mechanical property is important for the reliability improvement. Single crystal silicon is a brittle material, so the fracture strength depends on many factors. This research investigates the effects of crystalline orientations and surface morphology caused by micro fabrication process to discuss the fracture criteria on microstructures. [Applications] Database of fracture strength of single crystal silicon Design guideline of MEMS devices with hig   her reliability [Publications]  A. Uesugi, Y. Hirai, K. Sugano, T. Tsuchiya, and O. Tabata, Transactions of JSME, Part A, 2013, Vol. 79, Issue 804, pp. 1191-1200. A. Uesugi, Y. Hirai, K, Sugano, T, Tsuchiya, O. Tabata, The 17th International […]

Tensile strength of single crystal silicon microstructures

Silicon nanowire has excellent mechanical and electrical properties and is expected to be applies as nanostructure element of NEMS(Nano Electro Mechanical Systems). To prolong the life of NEMS and improve the reliability of them, it is necessary to reveal mechanical properties of SiNW. The objective of this research is tensile test of SiNW fabricated on MEMS device and investigate mechanical properties of SiNW [Applications] High speed and low energy consumption field effect transistor High sensitivity bio sensor Nano resonator

Tensile test of silicon nanowire by using electrostatic MEMS device

We demonstrated for the first time the versatility of the integration method of DNA origami on MEMS by selectively assembling it to form a bridge over a trenched silicon. A DNA origami (30 x 150 nm) was fixed to bridge the trench (100 nm width) utilizing the hybridization between DNA on the DNA origami and selectively immobilized complementary DNA-pattern at the edges of trench. This opens a way to integrate the nanomaterial components on a structured device such as MEMS by using DNA origami. [Applications]  Optical waveguide and one molecule detection sensor using GNP.  Field effect transistor using Carbon Nanotube. [Presentation] Y. Mori et al., “Selective assembly of DNA nanostructure bridging onto a trenched silicon substrate”, Transducers’15, Anchorage, AK (June, […]

Selective assembly of DNA origami bridging over a trenched Si ...

Carbon nanotube (CNT) is expected to be applied to elements of nano devices because of its attractive properties. We are developing a parallel integration of CNTs by the newly proposed method using single strand DNA (ssDNA). We are trying to electrically and mechanically characterize CNTs integrated by proposed method. [Applications]  Fabrication of CNT based sensors  Tens ile testing on CNT [Presentation] K. Hokazono et al., 28th IEEE International Conference on MEMS, 2015, pp.417-420. K. Hokazono et al., 6th Integrated MEMS Symposium, 2014.

Characterization of ssDNA modified CNTs

DNA origami is one of the most promising methods to form nano-scale structures or Nano/micro systems. However the effective use of DNA origami structures as building blocks for larger systems depends on knowledge of their mechanical properties, otherwise structures that provide specific mechanical rigidities or functionalities cannot be designed. [Applications]  Provide access to the development of new design methodology, effective fabrication process, and robust mechanics of DNA origami structures. [Publications] Z. Ma et al., DNA origami, Encyclopedia of Polymeric Nanomaterials, Springer Z. Ma et al., Direct characterization of radial modulus of DNA nanotube by AFM nanoindentation, NEMS 2015  

Mechanical properties characterization of DNA origami

Grayscale lithography has been attracting huge attention recent years as a solution to 3D microstructuring for MEMS applications. However, process parameters (e.g. exposure dose pattern, focal position and development time) here is highly coupled and needs to be decided by inefficient and time-consuming trial-and-error method. In order to improve parameter design efficiency and fabrication accuracy, a straight-forward “input target-out put parameter” optimization method is provided in this work. [Applications]  3D microstructuring based on grayscale lithography   MEMS, Micro fluidic system, Micro optical system, etc.   [Publications] X. Ma, Y. Hirai, etc., APCOT 2014, Daegu, Korea (June, 2014), 6-1 X. Ma, Y. Hirai, etc., 9246 SPIE Advanced Lithography 2015, San Jone CA (February, 2015)

Process Parameter Optimizer