Session: 01-02-04: Phononic Devices

Paper Number: 166213

Reconfigurable Non-Volatile Acoustic Devices Using Phase Change Materials 

Acoustic devices and components, including acoustic circuits, sensors, and filters among others, are based on material platforms exhibiting an appropriate spatial pattern of elastic constants with sufficient contrast to enable the confinement, control and manipulation of acoustic waves. Such devices are essential components of wireless communication technology such as cell phones. Traditional acoustic devices and components have a fixed pattern of elastic constant and therefore perform a single function. For example, cell phones contain many surface acoustic wave filters, each performing a single function. Considering the exponentially growing demand in wireless data transfer rates, the number of acoustic components in wireless technologies is bound to grow correspondingly and could quickly constitute a bottleneck in the development of advanced wireless communication. In this work we therefore presents a method and material systems for designing fully reconfigurable acoustic devices and components where the pattern of elastic constant can be endlessly reconfigured to enable a broad range of functionality in a single device. Moreover, the reconfiguration process is non-volatile and the reconfigured pattern of elastic constant persists indefinitely without the need for application of a magnetic, electric or optical field. The reconfigurable non-volatile acoustic devices are composed of a phase change material (PCM) made of a chalcogenide-based compound which can be switched between two phases through optical or electrical pulse actuation. PCM are used in many technological applications due their unique contrast in properties between the crystalline and amorphous phase. The contrast in optical properties is used for optical memories and optical computing while the contrast in electrical properties is used for computer memories and neuromorphic computing. Therefore these materials are fully compatible with advances fabrication methods such as CMOS and could be easily applied to the production of novel technologies such as acoustic devices. Here we use pulse echo measurements to demonstrate that the contrast in elastic modulus between the crystalline and amorphous phase of a PCM is up to 50% which is adequate to produce elasticity patterns allowing control and manipulation of acoustic waves. The switching process is permanent (non-volatile) but fully reversible, thereby enabling endless configurability into any spatial pattern of elasticity. We then use optical microfabrication with a mid-infrared laser source to demonstrate that thick films of PCM can be reversibly switched between crystalline and amorphous phases. This enables the production of complex patterns of elastic constants that can be endlessly reversed. This in turn opens the possibility of building highly compact phononic circuits with low losses and multiple functionalities.

Presenting Author: Wataru Takeda University of Arizona

Presenting Author Biography: Wataru Takeda is a postdoctoral fellow in the Materials Science Department at University of Arizona and a member of the New Frontiers of Sound Science and Technology Center.

Authors:

Wataru Takeda University of Arizona
Tanvir Shuvo University of Arizona
Howard Yawit University of Arizona
Zafer Mutlu University of Arizona
Pierre Deymier University of Arizona
Pierre Lucas University of Arizona