# US 2013/0210294 A1 · Underwater Robot Based on Flapping > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0210294 A1 - Document ID: US20130210294A1 - Status: Published application - Kind: A1 - Application number: 13/530,723 - Filed: 2012-06-22 - Published: 2013-08-15 - Earliest claimed: 2012-02-14 - Assignees: Snu R&Db Foundation - Inventors: Sung Hoon AHN; Hyung Jung KIM; Sung Hyuk SONG; Min Woo HAN; Gil Yong LEE - Web page: https://patentgrep.com/patent/US20130210294A1 ## CPC - B63G 8/08: Propulsion ({schnorkels B63G8/36;} nuclear propulsion B63H21/18; submerged exhausting apparatus F01N13/12) - B63H 1/32: Flaps, pistons, or the like, reciprocating in propulsive direction - B63H 1/36: swinging sideways, e.g. fishtail type - H02N 2/028: {along multiple or arbitrary translation directions, e.g. XYZ stages} - B63B 2035/007: {autonomously operating} - B63B 2231/28: Shape-memory alloys - B63G 2008/002: {unmanned} - B63G 2008/004: {autonomously operating} - B63G: OFFENSIVE OR DEFENSIVE ARRANGEMENTS ON VESSELS; MINE-LAYING; MINE-SWEEPING; SUBMARINES; AIRCRAFT CARRIERS (means of attack or defence in general, e.g. turrets F41H) - B63H: MARINE PROPULSION OR STEERING (propulsion of air-cushion vehicles B60V1/14; specially adapted for submarines, other than nuclear propulsion, B63G; specially adapted for torpedoes F42B19/00) - H02N: ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR - B63B: SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING (arrangements of vessel ventilation, heating, cooling, or air-conditioning B63J2/00; floating substructures as supports of dredgers or soil-shifting machines E02F9/06) ## Abstract Disclosed is an underwater robot based on flapping comprising: an actuator including a smart material and directional material, wherein the smart material is changed in its shape according to an external signal, and the directional material restricts a deformation in a specific direction; a body connected with the actuator; and a controller which makes the actuator perform a first stroke in a direction, and a second stroke in another direction being different from that of the first stroke; wherein the actuator performs at least one deformation of bending and twisting according to position of the smart material and directionality of the directional material, and furthermore enables to simultaneously perform the smooth bending and twisting motion with the simple structure by adjusting the position of the smart material functioning as the active component, and the directionality of the directional material functioning as the passive component. ## Claims ### Claim 1 An underwater robot based on flapping comprising: an actuator including a smart material and directional material, wherein the smart material is changed in its shape according to an external signal, and the directional material restricts a deformation in a specific direction; a body connected with the actuator; and a controller which makes the actuator perform a first stroke in a direction, and a second stroke in another direction being different from that of the first stroke; wherein the actuator performs at least one deformation of bending and twisting according to position of the smart material and directionality of the directional material. ### Claim 2 (depends on 1) The underwater robot based on flapping according to claim 1, wherein the directional material includes at least one of directional layer having a directional angle of 0°˜180° with respect to a longitudinal direction of the smart material. ### Claim 3 (depends on 1) The underwater robot based on flapping according to claim 1, wherein the directional material has anisotropic properties. ### Claim 4 (depends on 1) The underwater robot based on flapping according to claim 1, wherein the actuator includes at least one of first smart material for performing the first stroke, and at least one of second smart material for performing the second stroke. ### Claim 5 (depends on 1) The underwater robot based on flapping according to claim 1, wherein the actuator includes a first smart material positioned toward the direction of first stroke, and a second smart material positioned toward the direction of second stroke. ### Claim 6 (depends on 1) The underwater robot based on flapping according to claim 1, wherein the smart material is positioned out of a horizontal central plane and vertical horizontal plane of the actuator. ### Claim 7 (depends on 1) The underwater robot based on flapping according to claim 1, wherein the actuator has different twisting angles between the first and second strokes. ### Claim 8 (depends on 1) The underwater robot based on flapping according to claim 1, wherein the actuator produces thrust by the resistance difference of fluid between the first and second strokes. ### Claim 9 (depends on 1) The underwater robot based on flapping according to claim 1, wherein the actuator includes a matrix which supports the smart material and directional material, and determines an external shape, wherein the smart material and directional material are formed inside the matrix or in the surface of matrix. ### Claim 10 (depends on 1) The underwater robot based on flapping according to claim 1, wherein the controller induces deformation of the smart material by applying the external signal to the smart material. ### Claim 11 (depends on 1) The underwater robot based on flapping according to claim 1, wherein the controller controls thrust and lift of the body by adjusting intensity and application cycle of the external signal applied to the smart material. ### Claim 12 (depends on 1) The underwater robot based on flapping according to claim 1, further comprising a link part between the body and actuator, the link part including the smart material and directional material. ### Claim 13 (depends on 12) The underwater robot based on flapping according to claim 12, wherein the link part is connected with the actuator at a predetermined angle. ### Claim 14 (depends on 1) The underwater robot based on flapping according to claim 1, wherein the actuator includes a main actuator connected with front left and right sides of the body, and a supplementary actuator connected with rear left and right sides of the body. ### Claim 15 (depends on 1) The underwater robot based on flapping according to claim 1, further comprising a steering part for controlling a direction of the body, wherein the steering part includes a smart material, and a matrix for supporting the smart material and simultaneously determining an external shape. ### Claim 16 (depends on 1) The underwater robot based on flapping according to claim 1, wherein the smart material is any one of shape memory alloy (SMA), piezoelectric element, ionic polymer and metal composite (IPMC), or conductive polymer (CP). ### Claim 17 (depends on 1) The underwater robot based on flapping according to claim 1, wherein the directional material is formed of ABS (acrylonitrile butadiene styrene copolymer) resin. ### Claim 18 (depends on 9) The underwater robot based on flapping according to claim 9, wherein the matrix is formed of any one of elastomeric polymer, silicon, or polydimethylsiloxane (PDMS).