A PZT micro-actuated suspension for high TPI hard disk servo systems

A piezoelectrically actuated suspension for high TPI (Tracks per inch) hard disk drives is presented. Two reinforced piezoelectric microactuators, pla ced in parallel between the base plate and the spring beam, are used for th e secondary actuation, A stroke of 1.2 mum at the head was observed when dr iven by 30 V, The first torsion and the sway mode frequencies are 6.28 kHz and 10.5 kHz, respectively, In addition, the actuated suspension also has s ome distinguished features such as, a C-channel and meanderline springs for shock-resistance enhancement. A possible vertical motion of the suspension is helpful for contact-start-stop (CSS) friction reduction and gramload ad justment. It also makes the suspension free from twist due to two layers of piezoelectric plates on both sides of the beam. As a result, the developed actuated suspension can be used to support high TPI hard disk drive servo systems.