Scanning probe-type data storage beyond hard disk drive and flash memory

MRS Bulletin ◽  
2018 ◽  
Vol 43 (5) ◽  
pp. 365-370 ◽  
Author(s):  
Yasuo Cho ◽  
Seungbum Hong

Abstract

foresight ◽  
2008 ◽  
Vol 10 (5) ◽  
pp. 34-49 ◽  
Author(s):  
Tugrul U. Daim ◽  
Pattravadee Ploykitikoon ◽  
Elizabeth Kennedy ◽  
Woraruthai Choothian

2016 ◽  
Vol 119 (18) ◽  
pp. 184101 ◽  
Author(s):  
Tomonori Aoki ◽  
Yoshiomi Hiranaga ◽  
Yasuo Cho

Author(s):  
Shaomin Xiong ◽  
Toshiki Hirano

Abstract The data read and write operation in a hard disk drive (HDD) relies on precision mechanical components, such as air bearing sliders, suspension, and piezo actuators. Many of those mechanical components are sensitive to mechanical disturbances. It is found that sound a disturbance (or airborne disturbance) increases the position error signal (PES), such that the tracking, following and seeking performance is compromised. For a data storage enclosure and server in a data center, cooling fans generate strong sound noise, resulting in degradation of the performance of HDDs. In this study, we showed that the PES degrades when placing a sound source next to the HDD, indicating that the sound-induced vibration links to the mechanical components inside the HDD. It is also found that the PES is very sensitive to the location of the sound source. A vibration model was built by finite element method (FEM). The simulation results were compared to experiments on a thin plate structure to explain this dependency on the location of sound source.


Author(s):  
Yanning Liu ◽  
Sean Kang ◽  
Bo Li ◽  
Tung Nguyen

Hard disk drive (HDD) is a standard component of computer systems for data storage. With the advance of technology, increase of capacity and reduction of price, it is now used more and more in non-traditional computing systems, such as camcorders, portable video and music players, etc. These new applications have different emphasis on HDD performance compared to computers. They might not require very large storage capacity, super fast read access, but need high reliability under operational and non-operational conditions. In particularly, for portable devices, HDD has to survive common non-operational shocks during the daily usage of the devices. One design to improve HDD non-operational shock resistance is to unload read-write heads from media to a ramp after power off instead of leaving them on the medial at a special landing zone. A latch mechanism, such as the pawl latch studied in this paper, is then used to lock them on the ramp. During shock events, all the heads are well separated or limited by the ramp to protect them from hitting each other. Since the heads are off the media, they will not contact the media and cause data loss either. The reliability of load/unload (L/UL) drives, however, does not come free. Other than some design changes, which tend to increase cost, extra care also needs to be taken to load the heads to the media or unload them from the media to the ramp. This paper takes a close look at the inertia/magnetic latch non-operational shock performance and the actuator load process. Mechanical, servo and electronic systems are considered together to create a closed-loop simulation model. The effects of voice coil motor Kt drop off, magnetic latch torque bias, IR sensing circuit on load velocity variation are examined. The physical insights provided in the paper should facilitate the design of HDD.


1996 ◽  
Vol 118 (2) ◽  
pp. 402-406 ◽  
Author(s):  
C.-P. Roger Ku

Recently, many computer hard disk drive companies and spindle motor manufacturers have been looking for a substitute for ball bearings to continue making dramatic progress in increasing the capacity of data storage systems. In this paper, the frequency-forced responses of hard disk drive spindle motors supported by both ball bearings and liquid-lubricated spiral groove hearings (SGBs) were studied experimentally. It is found that both shaft rigidity and disk flexibility have great effects on the natural frequency of the spindle motor conical (rocking) mode. The high damping capacity of the SGB is able to suppress the vibration amplitudes of both motor rocking mode and the flexible disk modes. But at a very low frequency range, the SGB motors displayed a large amplitude in the axial direction vibration test. With an adequate bearing design, the SGB motors have proven their superior dynamic characteristics.


Author(s):  
Jiaping Yang ◽  
Cheng Peng Tan ◽  
Eng Hong Ong

Heat transfer issue has become a challenging task in designing a high power density data center. As power consumption (Watts) of the data center continues to increase, effective thermal management of computing clusters, servers and data storage systems in data center will become more and more demanding. Hard disk drive (HDD) as a key power consumption device in high-end data storage system, its heat transfer issue has attracted more research attentions due to its complexity in nature of enclosure air flow driven by spinning disks. Among various thermal management solutions, one promising approach is to enclose helium rather than air in the hermetically-sealed hard disk drive as to reduce windage loss and flow disturbance. This paper investigates the thermal performances of disk drives where their enclosures have been filled up with helium and various helium-air gas mixtures using FEM simulations and experimental validations. Windage loss and heat convection of the disk drives being filled up with helium or helium-air mixtures are compared and analysed. The results show that helium-filled HDD provides heat transfer enhancement capability than the air-filled HDD by achieving up to 41% reduction of average temperature rise. Furthermore, 40% reduction of magnetic transducer position error signals (PES) was experimentally observed in helium filled HDD. Enhancing heat transfer and better PES quality via helium gas will greatly improve HDD read/write reliability and increase track density capability for data storage systems in data center.


2009 ◽  
Vol 48 (9) ◽  
pp. 09KA18 ◽  
Author(s):  
Yoshiomi Hiranaga ◽  
Tomoya Uda ◽  
Yuichi Kurihashi ◽  
Hikari Tochishita ◽  
Michio Kadota ◽  
...  

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