System and methods for fabricating actuators and electrically actuated hydraulic solid materials

Abstract

With applications such as soft robotics being severely hindered by the lack of strong soft actuators, the invention provides a new soft-actuator material—Electrically Actuated Hydraulic Solid (EAHS) material—with a stress-density that outperforms any known electrically-actuatable material. One type of actuator is fabricated by making a closed cell that acts as highly paralyzed version of a standard paraffin actuator. Each cell exhibits microscopic expansion, which is summed to produce macroscopic motion. The closed cellular nature of the material allows the system to be cut and punctured and still operate. It can be produced in a lab or industrial scale, and can be formed using molding, 3D printing or cutting.

1 . An Electrically Actuated Hydraulic Solid (EAHS) material comprising:
 a phase change material (PCM);   an elastomeric polymer material;   a conductive material, the phase change material and the conductive material embedded within the elastomeric polymer material forming a conductive elastomeric structure, wherein the PCM undergoes a phase change as controlled by the conductive material to vary an internal pressure and actuate the structure.   
     
     
         2 . The EAHS material of  claim 1 , wherein the phase change material forms a plurality of closed cells encapsulated by the elastomeric polymer material. 
     
     
         3 . The EAHS material of  claim 1 , wherein the conductive material is randomly distributed through the elastomeric polymer material. 
     
     
         4 . The EAHS material of  claim 1 , wherein the phase change material is paraffin wax. 
     
     
         5 . The EAHS material of  claim 1 , wherein the elastomeric polymer material is Polydimethylsiloxane (PDMS). 
     
     
         6 . The EAHS material of  claim 1 , wherein the elastomeric polymer material is a two part elastomer. 
     
     
         7 . The EAHS material of  claim 6 , wherein the phase change material is added to one precursor of the two part elastomer and the conductive material is added to the other precursor of the two part elastomer. 
     
     
         8 . The EAHS material of  claim 1 , wherein the elastomeric polymer material is a one part silicone. 
     
     
         9 . The EAHS material of  claim 1 , wherein the conductive material is carbon black. 
     
     
         10 . A method for fabricating EAHS material comprising the steps of:
 combining a phase change material, a conductive material, and an elastomeric polymer to form a conductive elastomeric structure with closed cells of PCM.   
     
     
         11 . The method for fabricating EAHS of  claim 10 , wherein the phase change material forms a plurality of closed cells encapsulated by the elastomeric polymer. 
     
     
         12 . The method for fabricating EAHS of  claim 10 , wherein the conductive material is randomly distributed through the elastomeric polymer. 
     
     
         13 . The method for fabricating EAHS of  claim 10 , wherein the phase change material is paraffin wax. 
     
     
         14 . The method for fabricating EAHS of  claim 10 , wherein the elastomeric polymer is Polydimethylsiloxane (PDMS). 
     
     
         15 . The method for fabricating EAHS of  claim 10 , wherein the elastomeric polymer is a two part elastomer. 
     
     
         16 . The method for fabricating EAHS of  claim 15 , further comprising the steps of:
 adding the phase change material is added to a first precursor of the two part elastomer;   adding the conductive material to a second precursor of the two part elastomer; and   combining the first precursor and the second precursor.   
     
     
         17 . The method for fabricating EAHS of  claim 10 , wherein the elastomeric polymer is a one part silicone. 
     
     
         18 . The method for fabricating EAHS of  claim 10 , wherein the conductive material is carbon black. 
     
     
         19 . An actuator comprising an EAHS structure including both a phase change material (PCM) and a conductive material, the PCM having a phase change temperature greater than a temperature of the structure, wherein a current applied to the conductive material causes the PCM to expand and actuate the structure. 
     
     
         20 . The actuator according to  claim 19 , wherein the EAHS structure is confined by an external casing so that EAHS expansion causes linear expansion of the structure.